Is there a way to present a group's detail section in columns without segmenting the group header into columns?

I have pre-printed 8.5x11" pre-printed forms with 3 forms per page.
Each form has a detail and header section.

I thought about using a sub-report in the detail section but I have to print 8" across and I can't keep the sub-report from adding its own margins and since my minimum margins seem to be .25" the forced margins of the sub-report mess me up.

Any help would be greatly appreciated.