Thanks for all the help! Couldn't find that stupid gate stupid me! Found that crappy lich btw! Funny surprise, killed me and my grp. after the time stop! What a shithead! =) What lvl is that lich`? Any idea?

Thanks for the help anyway! =)

Let me guess, you have accidentally ran into the lich at the city gate??
Here are couple of spells that can work well gainst lichs:
1) false dawn (cleric)
2) sunray (cleric)
3) bolt of glory (cleric)
4) holy smite (cleric)

Tip: Cast protection from evil on your party before you enter the room, the lich often "gate" a pit fiend after a time stop. When you enter the room, stay back near the entrance, that the pest do the normal lich drill (ie. fireshield...timestop...da da da) and when he summon the pit fiend, 9 out of 10 times they will fight each other, let the pit fiend finish the lich. Then walk out, rest (pit fiend will be unsummoned inside the lich room), walk back into the room and collect the loot.

If you have the proper equipment (like weapon with bonus vs undead or high level magical enchanted weapon like the talking sword), you can try your luck hacking and casting through the lich. Have fun!!