Force Excel to Open Multi Files in Same Instance

Greetings, Gurus.

All the buyers at work use an Excel workbook containing macros when performing edits to purchase orders. I created the workbook and macros about 4 years ago, (with the generous help of the contributors on this site), in Excel 2003. The idea is that the buyer opens the master workbook, and then leaves it in the background while running the macros in that workbook on other Excel files that they open up, received from the vendors via email. In order to do this, both files must be open in the same instance of Excel.

Though the macros were written in Excel 2003, and we were running on Windows XP Pro, I had no problems when the company upgraded to Excel 2007. Now we are implementing Windows 7, and I'm having a problem.

I can't figure out how to make Excel open a new file in the already open instance of Excel when they double-click the file from their email so that the macros will be available. A web search said I should "check" the box in Excel Options/Advanced that says "Ignore other applications that use dynamic data exchange (DDE)", so I tried that, but it didn't work.

Does anybody know how to force Excel 2007 to open another Excel file in the same instance of Excel in Windows 7 when the file is double clicked? (Right now I've got her saving the file to her desktop and opening it from the original Excel file by using the "File/Open" command, but that requires extra steps we would prefer to avoid.)

Thanks in advance for any help you can offer.

Hutch

Need to bump this one. I haven't figured it out yet. Let me know if the problem isn't clear.

Thanks.

Thanks, Joseph. I'll give it a shot.