Can I insert break point into source perl program?

Have you tried adding the -d switch to the shebang line at the top of your script? Something like

#!/usr/bin/perl -d
use strict;
use warnings;
$|=1;$\="\n";

print "Test";

It really depends exactly how it gets launched, but at least in simple cases this should start the debugger.

Edit: You can then set a breakpoint on a specific line with a certain condition using

> b [line] [condition]

and hit

> c

to continue with running the script - the debugger will stop at the specified line when the condition is met