mix'n match GXP2000 and SPA3102

I know this is a trixbox forum, but I heard this may also be the place to drop a question or two about the grandstream. I have a nice shiny new GXP2000 which just arrived today, and as yet I do not have a trixbox running (although i do plan to work on it over the coming weeks/months).

In the interim, I would like to configure the granstream to "work with" my linksys (sipura) 3102. I'd like to associate one of the grandstream lines to the PSTN line of the sipura, but have no idea on this earth how I would achieve it. So really I need someone who knows a bit about both units. I'm guessing it would be something simple like a dial plan, dialing rules or forwarding setting applied in the sipura, and associating one of the grandstream accounts to it, ie instead of entering regular VOIP provider/account details, you would enter the sipuras details.

Yes, I know trixbox will also do all this, but I am after a quick fix until I get some time off to do this. I promise I will do it, but for now, I just want to make PSTN calls on the grandstream. Can anyone help?

Thanks and regards

Dave