Subreports in columns

I have a report with 5 subreports, all in stacked nicely in Group Headers. I've enabled columns in the main report, and formatted the subreports so they all fit within a single column. My problem is that I need to have the 4 smaller subreports in the left column, and the longer 5th subreport appear alongside them in the right column. Is this possible? They are in the main report like this:

GH1a   Sub1

GH1b   Sub2

GH1c   Sub3

GH1d   Sub4

GH1e   Sub5