One of the first things I did was try enclosing the filename in quotes. It's interesting you mention the "?" being used for globbing. When I enclose the file name in quotes in the shell, tools like xcopy work fine, but Perl cannot see the files. So does the perl filetest glob?? I'm thinking not.
I'm wondering if the DOS shell passes that along expecting globbing to take care of the unsupported charachter. If that's the case, I can try replacing the "?" in the file names with literal 0x3F's. Hmm, I'll be giving it a try.