If you only have FTP access, I assume you can't write to the perl library directories, so you could upload other libraries to $ENV{HOME}/perl/libs and put

use lib "$ENV{HOME}/perl/libs";
[download]

at the top of your programs.

Note: Any libraries with XS code may have problems, since they have to be compiled locally, then uploaded. This should work for all perl-only modules.

Update: Changed ' to " because variable is used.