Why do you want to lie about the filename? This will make debugging your construct horribly bad, as you can't be sure which file to open to find the root cause of a warning or a crash.

See perlsyn about comments. The following code should show you how to make Perl claim and a module believe it is loaded from another file:

eval qq[\n#line 2001 ""\ndie 'foo']; print $@;
[download]

You might also want to set up %INC appropriately.