3 to 45?
Seriously? Unless your DM is throwing the books out the window at about 24th level, just make whatever you want to play the most, as by then wizards and clerics get infinite everything and everyone else automatically dies. \ o /
More seriously though: I'd avoid the Warlock. It's a class that only shines with either careful building and meticulous cherry picking of items and cross-classing (Hellfire Warlock+Chausible+Arcanum crap) or if your DM is one of 3 who will actually throw like ten encounters at you with no chance to rest.
Why not play a Cleric of Wee Jas (assuming the Greyhawk/3.5 Default Pantheon) or Anubis or Evening Glory? You still have the creepy undead angle to play with (and Clerics are easily the single best class, mechanically, to be if you want to fiddle with the undead), and everyone will love you in a party because hey! You can heal them or buff them or anything else you want to while also being able to walk around in a heavy tin can of armor and hit things with blunt pieces of metal until they fall over!
AND on top of all that, everyone knows none of those deities are evil, so as long as you aren't walking around with a shambling entourage of the undead, you['ll be more than able to go wherever you want for the most part, and shouldn't have too many issues with the party Paladin. =>