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Hotel California - absolutely remember it - great song.  It sounds like in your instance the line my aptly apply.  Does Excel or QB have an SIE add in to support this format so that you can export current data in QB to SIE and then select SIE as the file to import in Excel?  Here in the states (whenever there used to be competition among many software companies they would provide support (some better than others depending on the software) that would support data from vendors such as dBase, Paradox, CSV, Tab Delimited and the like.  One option that I've used in the past is to actually "print to file" in .txt format then programs like Excel give you the option on import to view the data allowing you to see the layout (since it is in column form) and specify the width for each column and the option to either import or skip column(s) that are not necessary.  I have found doing this in QB there are two problems that can be problematic and for me the former.  1) Despite setting an almost infinite page width that would certainly accommodate the split accounts and the memo fields they will still sometimes be cutoff only showing partial split; memo; or any other long text.  The second problem (as I recall been some time since I attempted this) is that on reports where the split categories are listed it will just show "split” and a total amount in the print to file report; thus, no multiple lines that show the split category with the amount for each category.  Finally, the print file must be printed to Generic Text as the selection if you forget and print to file but still have your printer selected as the source it will more than likely export gibberish with all the printer codes for italic, bold, font size, etc...  A possible solution is a vendor and they might have or be able to develop support for the SIE file type you mention.  (I have no affiliation with other than being a former user) who could perform all these operations and more by interfacing with QB to allow mass changes such as import/export, categories merging data from multiple company files into a new combined company.  This is handy if someone has a file for their company and another file just setup for individual use to balance personal accounts.  For instance, small business operators who pay for business items or auto fuel personally for reimbursement later.  It allows them to combine the data from business and personal (selecting only the necessary categorized transactions (ex. reimbursable expense to more effectively get an idea of the inflows/outflows of a business in one location.  This can then be printed or exported to Excel without the need for jumping back and forth between company files with two reports to view or two exports to Excel.  And it does give you a warning up front that it will need to access your company file.  But not in the sense that you must "sign into an online account."  It just meant (to me) that in order to perform the necessary operations the program had to access the company files.  As an extra precautionary measure, I would disconnect from internet just before and during my usage of the program and it performed flawlessly.  I found no program hiccups but any errors are lack of concentration such getting up at 6am and still working at 2am the next morning semiconscious.  The program is used was at the time called Transaction Import Pro (TIP) you might inquire with them if they have or could develop import export support in your country.  This program though is designed for people who've been around computers and it is always important to have regular backups of all company files daily and before attempting any import export operations particularly the individual company files that are being combined into a new company file.  (I think it even provided the ability to append data from one Company to another but I would not recommend that option) The other thing it allowed for was the ability to bring in transaction data from other sources besides QB in batch.  It also allowed much greater power in exporting out of QB to Excel or Relational Database.  (Really does anyone have time to screw around with Intuits transaction import kit directions (not to be confused with program I'm talking about) for importing data only to find there's still much editing to be done and to discover it would have been faster to do it all by hand?  I used Transaction Import Pro a few years back and really liked it; however, after four or five years of new QB versions it became obsolete. I believe though as a former user I have a lower upgrade price to get to the newest version.   Since I only used it on an occasional basis, I currently cannot justify the expense.   Here's a link to their site for anyone who might think it's necessary.   https://www.transactionpro.com/ 
In Summary: To me it’s pricey but worth it for those familiar with importing and exporting and need its power on a regular basis.