Here are a couple of things you can do:
1. Right-click on the subreport and select "Format Subreport...". Turn off the borders on the subreport.
2. Right-click on the subreport and select "Size and Position". Set the X and Y coordinates both to 0. This will place the subreport at the top-left of the section where it's located.
3. In the subreport, suppress ALL of the sections that you're not using.
4. Make the height of the subreport fairly small - it will expand to the size of the data it contains.
5. Put the column labels in the Page Header of the main report, using markers on the ruler to identify the placement of the left side of each column header. Be sure to line the markers up to a specific "tick mark" on the ruler.
6. In the subreport, place markers at the same tick-marks on the rule as you used for the column labels on the main report. Then align the fields in the subreport with the markers.
This should get you close to the format you're looking for. If it's not exact, you can look at the report in Preview and tweak the position of the column labels to match the data in the subreport.
-Dell