firewall blocking cpanel

I'm trying to access Cpanel controls for a website/hosting site. I believe it's being blocked by my linksys router, though. Getting Cpanel to work should just be a matter of unblocking those particular ports in the Linksys firewall, correct? How do I do that? The router is a WRT54G.

And yes, I have looked for a guide online to this problem, but the only thing I found was giving instructions to change your IP address and stuff like that, which I didn't think would be necessary at all. I thought it should just be a matter of allowing traffic through the right ports.