From the output you supplied, it sounds as if the initial shebang line is not correctly executing the Perl interpreter in the first place. Are you sure that line is correct in your script? You might try a really simple test program to see:

#!/path/to/perl
print "Hello, world";
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If you've got the shebang right, this should just output Hello, world when you execute it.

As for use lib, what you probably really want to do is this:

use lib '/export/home/jones/perl/lib/perl5/site_perl/';
use LWP::Simple;
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The first line basically says "when I write use Something, make sure you look in /export/home/jones/perl/lib/perl5/site_perl/ to find Something.pm."

The second line actually uses the LWP::Simple module (appending lwp/Simple.pm to the path specified by use lib).