Your specification seems not to be clear ... however you should try to replace

next if ($username =~ /ipw\.a^a-ma-z*/);
[download]

by

next if ($username =~ /ipw\.a[a-m][a-z]*/);
[download]

That way names like "ipw.ammmmawert" would be skipped, but "ipw.anawert" wouldn't.

HTH, Rata

PS.: PLEASE work on your formatting!

update: removed one small ^ (with a big effect)