Here's what might work as a way to hard-code multiple surveys into one script. I know it's a little hackish, but I'd like a solution that works sooner rather than waiting several months to learn Perl first (I do have bills to pay; and the website needs to be functional.):

Replace the line near the top:
$JUMP_URL="$ENV{'HTTP_REFERER'}";

with:

if ($survey_name eq "01howfound"){
$JUMP_URL="http://www.webmonkeydean.com/et-toi/";
}
if ($survey_name eq "02swampopera"){
$JUMP_URL="http://www.webmonkeydean.com/et-toi/schedule";
}
# repeat for more surveys
else{
$JUMP_URL="$ENV{'HTTP_REFERER'}";
}
[download]

And use $JUMP_URL as the links like this:
<a href="$JUMP_URL">Continue</a>

(In case you wonder "why not just use '$JUMP_URL="$ENV{'HTTP_REFERER'}";'", it wasn't working sometimes-- possibly because of firewall blocking.)