Use the Content-disposition header, like so:

print "Content-type: application/msword\n";
print "Content-disposition: attachment; filename=mydoc.doc\n\n"
[download]

perl -pe '"I lo*`+$^X$\"$]!$/"=~m%(.*)%s;$_=$1;y^`+*^e v^#$&V"+@( NO CARRIER'