There is an example in the documentation for tieing to a remote registry...

use Win32::TieRegistry( Delimiter=>"/", ArrayValues=>0 );
$remoteKey= $Registry->{"//ServerA/LMachine/System/"} or  die "Can't r
+ead //ServerA/LMachine/System/ key: $^E\n";
[download]

You will need to have permission to access that registry as the user you are running the script as, I don't believe there is any mechanism provided for you to provide alternate credentials to Win32::TieRegistry.