Nah, we can show the users how to use edit/replace, it'll work fine for their file. However, there is a new development. One of the end users got it to work as a .csv. I tried it too, and it worked. Here's the pertinent part of the email she sent:

"I got it to work as a CSV file. The end result gets me the semicolon. Go Excel Options/ Advanced/Editing Options Decimals and uncheck system separators and put in a comma in the decimal field. Then you need to save the file as a CSV file…it will automatically put in a semicolon between fields. I still don’t have a solution to the txt files but at least this works and most systems have no problems reading CSV files. And no it doesn’t change the decimal in the file to a comma or a semicolon".

So there ya go. Thanks for your input, by the way.

I'm still wondering if my original expectations are correct, the semi-colon should not be in the file once the .dat is opened in Excel? If anyone can confirm or expand on this I'd appreciate it.