Well, I guess you are running into trouble, cause there's one key but more values to it. So you better read the query string and stuff all remitted vars in separate array's or hashes first and then go down to single key-value pairs.
But if you'd like to use CGI.pm, as suggested, you you could use something like @wanted = $query->param($remitted), where $remitted is the key.
Do you think, your employer would allow you to tune up that script with cgi.pm ???
Have a nice day
Update
Ok, as I see, others have been faster :-)