I want to create a userform to display 2 dropdown lists, both with all
currently opened XL files in the list, so the user can select 2 files
to compare.

I've tried reverse engineering Chip Pearson's code in his "Compare"
macro, but it's just beyond my current skill level. And I looked for
information in this NG, but couldn't find a solution, probably I just
don't know how to phrase the search criteria correctly.

I have almost no experience with forms in XL, other than creating a
simple form to ask the user for input and put the data in a cell. But I
do know how to create a basic form.

Thanks.