in reply to Re: CGI : How to put an "&" into a GET-parameter
in thread CGI : How to put an "&" into a GET-parameter

So use escape(), from CGI::Util. It comes with, and is also imported into CGI.pm. You can use it as a function, or as a class/object method:
$escaped = CGI::escape($string); $escaped = CGI->escape($string); $escaped = $cgi->escape($string); # if $cgi is your CGI object