Javascript: clientside (in your web browser)
Perl: serverside (on the webserver)

The only way you are going to get anything like an on click is to use an anchor and link to a cgi directly:

<a href="program.cgi">Click here</a>

or (untested but would only work on IE)
<img src="blah.gif" onClick="self.location=program.cgi">
[download]

But you really want to avoid the latter example.