Redirection in PHP

Keyword based...please help...

[holyearth]

I know for you guys this should be easy...

Looked all over and I can't find it :-(

Here's a PHP script I need (it's easy).....

User comes to www.abc.com/index.html?keyword=sxtmak

I need user to go to www.xyz.com/index.html?subid=sxtmak

Another example....

User comes to [INCOMING_URL]/?keyword=product245

I need user to go to [OUTGOING_URL]/?subid=product245

I used to have the PHP script to redirect for this kinda thing, but I lost it along with a server crash! Could a nice soul whip this up for me?

Thanks and God bless in advance!

[holyearth]

Got it!

<?php

header("location: [outgoingurl.com?subid=".$_GET['keyword']);...]
exit();

?>