arghhh!

I just got sent an ipaq rx1950 and im trying to setup an ad-hoc connection from my laptop to my pocket pc. I want to share my dialup connection so i can surf on the pocket pc. I've tried guides with no luck. I managed to get it working for a minute or so but then it drops out. Its because the ip of my ppc keeps changing and ive tried fidling with the ip setting on comp. and ppc.
What are the exact setting i should use?
thanks