Rebel XTi WB Question

I'm shooting a stage show next week and I will bring my (so far) trusty 1D3 as usual, but a friend lent me his Rebel XTi to use as "backup", probably will use it for the odd wide angle (and have the 70-200 on my 1D3).

I notice the WB on the XTi limits itself to 3200K as the lowest preset and there is no manual way to enter WB, so I was wondering, if I wanted to get to about 3000K (my usual setting on my 1D3 for these), how much B(lue) would I need to dial in on the WB shift to get close?

The best solution would be to shoot raw and then set the colour temperature of all of the pictures at once in post.