Need help putting together a fun NPC :D

[E_Samurai]

Hey guys, I've been asked to sit in on a group's game, and I've been offered an NPC to fill in for the time being. The DM is allowing me to re-stat the character, and I'd appreciate any suggestions you can offer.

The character is an iconic dwarven general, accompanying the group while escaping a siege on his home city. He's currently set up as a pretty standard dwarven tank, using a two-handed great-hammer and a set of mithril full plate. I'd like to keep the look and feel of the character the same, but change his mechanics so he works better with the rest of the group.

Here's the tricky part - I don't want to upstage the group's fighter, so he shouldn't be dealing a large amount of damage in combat. Instead, I'd like to build him as more of a battlefield controller - charging into a group of enemies and send them flying in all different directions like a bowling ball into pins, while the fighter gets in the actual kills. Specifically, I'd like the character to be attacking several different enemies after a charge, and dealing knockback to each one. Also, he should be virtually indestructible, although his high Constitution and the full plate armor should help in that regard.

The character is currently 6th level, and pretty much all books are allowed, although he's specifically disallowing Shock Trooper / Leap Attack cheese and the Frenzied Berserker class, and he'd like to review the build once it's done. The DM has graciously offered to let me use the Knockback feat from Races of Stone even though I don't qualify for it - Awesome Blow would work quite well, if only it weren't a standard action. I'm thinking Warblade or Fighter with a dash of Barbarian might be appropriate.

Any ideas, guys?