It is possible to use another character (other than "/") to make a regex. A hash symbol can be used for example:

$changeme = "/this/url/would/be/a/nightmare/in/regex/";
$changeme =~ s#would/be#is/not#;
[download]

You can also escape all special characters in a regex with "\Q" and "\E" like this:

$changeme = "/this/url/wo*ld/b^e/a/nightmare/in/regex/";
$changeme =~ s/\Qwo*ld/b^e\E/\Qis/not\E/;
[download]