Redirecting multiple dynamic (php) pages?

Please bare with me if this has already been asked before but I have
been trying to figure out how to use .htaccess to redirect dynamic
PHP-pages?

The situation is this. I am running a site on a virtual server running
Apache. I have access to modify .htaccess for whatever directory I
want but I can't make changes to the Apache configuration (as far as I
know).

At the site we have been running an old forum software that by now is
heavily indexed in Google. Recently we upgraded to a new forum
software and I want to redirect the users who through search engines
find indexed topics in the old forum to the new one.

The URL:s in the old forum looks like this:

http://www.allamedia.com/forum/viewtopic.php?TopicID=3895

.... and in the new forum like this:

http://www.allamedia.com/ipb/index.php?showtopic=3895

How can I redirect people who try to access the first URL (and any URL
like it) to the second URL?

Any help is much appreciated!

Why don't you just solve this in PHP?

/forum/viewtopic.php

<?php
list ($oldname,$ID) = explode ("=",$QUERY_STRING);
header ("Location : <a style='text-decoration: underline;' href="http://............./ipb/index.php?showtopic=" target="_blank">http://............./ipb/index.php?showtopic=</a>".$ID);
?>

cheers

Niels


"Manolo Hernandez" <mh.RemoveThis@empty.newcamp.net> wrote in message
news:34b023ca.0402190232.1b027887@posting.google.com...
 > Please bare with me if this has already been asked before but I have
 > been trying to figure out how to use .htaccess to redirect dynamic
 > PHP-pages?
 >
 > The situation is this. I am running a site on a virtual server running
 > Apache. I have access to modify .htaccess for whatever directory I
 > want but I can't make changes to the Apache configuration (as far as I
 > know).
 >
 > At the site we have been running an old forum software that by now is
 > heavily indexed in Google. Recently we upgraded to a new forum
 > software and I want to redirect the users who through search engines
 > find indexed topics in the old forum to the new one.
 >
 > The URL:s in the old forum looks like this:
 >
<font color=purple> > <a style='text-decoration: underline;' href="http://www.allamedia.com/forum/viewtopic.php?TopicID=3895</font" target="_blank">http://www.allamedia.com/forum/viewtopic.php?TopicID=3895</font</a>>
 >
 > ... and in the new forum like this:
 >
<font color=purple> > <a style='text-decoration: underline;' href="http://www.allamedia.com/ipb/index.php?showtopic=3895</font" target="_blank">http://www.allamedia.com/ipb/index.php?showtopic=3895</font</a>>
 >
 > How can I redirect people who try to access the first URL (and any URL
 > like it) to the second URL?
 >
 > Any help is much appreciated!<!-- ~MESSAGE_AFTER~ -->