Without removing the head, I think the best shot you have is to renistall a belt as best you can and rotate to TDC. Assuming nothing has rotated since the belt was removed my guess is that you will be within 1 or 2 teeth of being right.
I would suggest to remove the plugs and rotate the engine by hand.
That is my $0.02, no guarantees.
Warren
88 325iX
91 318is
95 525iT