I'm not entirely clear what you mean, but does something like thid do the trick?

my $file_path 
   = 'home/sites/site18/users/rjoseph/web/images/image1.jpg';
my $path = '/home/sites/site18/users/rjoseph/';
$file_path =~ s/^$path//;
[download]

--
<http://www.dave.org.uk>

"Perl makes the fun jobs fun
and the boring jobs bearable" - me