WRT54G non standard portmapping??

Hi all,

I recently purchased a WRT54G and am running it with the latest official linksys firmware.

I used to have a BEFXXX Wireless B router.

In my old router I was able to setup port forwarding with different inbound and outbound ports, but I cannot for the life of me see how to do this on the WRT54G.

For example

I can easily setup standard port mappings like for SSH

Internet -> PORT 22 ROUTER PORT 22 -> COMPUTER

But I want say to do:

Internet -> PORT 9212 ROUTER PORT 22 -> COMPUTER

How can I do this?

mj