THAT DAMN magic barrier in the dungeon (chap2 murder in umar hils) has me stumped i have to kill the shadow lord but how do i get to it when i can not get past the barrier (hints or help PLEEEESSSE)

Well, I assume you're talking about the barrier made out of shadowy stuff. As far as I remember, you need to go north across some sort of 'canyon' (with lava underneath). You don't have to break that barrier, you just need to get around it.

Bit-o-spoiler

There is a blue barrier that blocks the left section off as you go in. In solving the correct part of the questions from the head in the northern room, you will open this barrier.( there are 3 parts you need to answer all correctly. dawn, noontime, dusk rituals- I just stuck to finishing them all and had Minsc use the red dragon armor to nullify the flamestrikes when I was wrong here.) Finishing the 3 sets of questions will net you a piece of the key.

Once past this, you will go southward til you see the next barrier. Instead of trying to go thru it, go to the right side and kill undead and get stuff in the lava, walls, and column. Then proceed til you see some phantoms. Give them the remains of the child prophetes and you will collect a ward stone. Now you should be below the second barrier and continue to head south.

A section will be visible where you go eastward. You have to go there to get a third piece of the "key". There is a floor riddle here. I'll leave that up to you. Kill undead, go to the two rooms and get the loot from the left and key part from the right. Once you have all 3 pieces, they will combine and you are now set to continue thru to the shade lord. Go back to the hallway and head south and then it turns eastward. You can go thru the barrier and then hit the stairwell.

After you zone into the next area, there is a dormant dragon there. A passage to the left will take you outside to the shadelord. I opted to whack the dragon first and then save and hit the shadelord.

Hope that helps

You need the mentioned key to access the dragon and shadow lord.
On the first level of the temple ruins there are 3 *shadow doors* and you can find 2 sun gems to open them. Pass the 2nd *shadow door* in the way described above and use your gems for the other two.