Thanks for the reply.
I can do all that, and then the drawer front will line up perfectly
with the drawer box. But, if the slides for the drawer are not
perfectly aligned, then the drawer boxes will not sit perfectly
parallel. Even a 1mm difference will be noticable when the drawers are
closed, as they are about 80cm wide.
So, I am wanting to align the door fronts with each other and with the
frame, which may mean that they are not perfectly aligned with the
boxes inside, but that is no problem.
I hope that this is making sense - I'm finding it hard to explain.