This is quite off-topic, since it has nothing really to do with Perl, yet, I'll try to help you out.

Launching a ./Program.pl means, "Please, shell, launch the script Program.pl which is located in ./" The dot-slash means the current directory you're in. You could use /home/Programs/Program.pl in any directory, but that's quite annoying to type every time.

If you set the path in your ~/.tcshrc, as specified, you should be able to call Program.pl without a problem (drop the dot-slash in front of it).

Another thing that strikes me as odd, is the fact that you speak of a ~/.tcshrc (tcshell), yet the error is coming from bash (another shell). So you probably want to add the following line in your ~/.bash_profile:

PATH=$PATH:/home/Programs
export PATH
[download]

This way, you alter the path for bash (which you seem to use anyway). Save these additions to ~/.bash_profile (or ~/.profile) and the next time you login, you can launch your script by typing "Profile.pl" :)