@INC holds the paths that Perl searches to find the modules. The modules are specified with use. So be clear that they are separate issues you are talking about.

1. The error you get shows that Net::FTP is not in the standard @INC path. Have you installed the module? I don't know if it is now in the standard distribution but it didn't used to be.

2. If you have installed it but not to the standard directory, you should add that directory to @INC. Do not push to @INC, rather do this:

use lib '/export/local/perl'
[download]

Before you call use Net::FTP

-- iakobski