Raimbaud is a wild and wooly start. I tried 5 times, and all 5 times the Seljuks opened the game up by declaring Holy War for Edessa.
So either you get lucky and they don't do that in your game, or you have to get land somewhere else very, very fast.
Fifth time I tried it I happened to draw a very good set of starting stats, including Elusive Shadow, and managed to assassinate my way to inheriting from Vahram in February 1073 - while the Seljuks were just wrapping up sacking Aintab.
Immediately surrendered to the Seljuks (no point dragging that war out). Now I've got 10 years peace before the Seljuks come back and kill me. I figure if I want it, I could now conquer the world eventually - just sail away to Hispania.
Or I could vassalize to ERE and convert to Orthodoxy. Forge a claim somewhere on the west border of ERE, press it to secure an escape route in case Seljuks come back. Try to get a marriage between my heir (when I get one) and someone with an inheritable claim to ERE, and two generations from now I'd be set to become Emperor.
The serious challenge would be to stay Catholic Norman, stay east of Sicily, and still try to make this work; I'm not sure I see any easy solutions for that puzzle.