Run doesn't work in xlstart reference file

I have 2 workbooks in my xlStart folder. wb1 references wb2.
When I start Excel, wb1 opens first, which automatically opens wb2 BEFORE wb1!Workbook_Open() runs.

During wb2!Workbook_Open(), "Run(myprocedure)" doesn't run. At the end of wb2!Workbook_Open(), wb2 tries to close, and I get an error message saying "Workbook cannot close because it is referenced by another workbook", and doesn't close.

Is there some way to tell Excel which workbook to open 1st? Or some other kind of help?

Why not only have one workbook in XLSTART and have it open the other workbook in code?

Sometimes it helps to talk to a simpleton like me - I tend not to think of anything complicated!