How to create report of multiple form which are not linked by lookup -

Hi,

I have a form - which in turn has a subform. They are not linked by lookup. It has a 1 to many relationship.
I need to form a report with data from main form and subform. Only problem is that the multiple rows of the subform data comes together in one cell/row. I need to have them in seperate rows
For Eg

Main Form      Subform
A                  A - 1
                  A - 2
B                  B - 1
                     B-2
                     B-3

After looking at the advise given in other posts, i thought of putting a lookup.. but that does not make sense.
Is there any way to join the 2 forms to make the report - They are joined by the Ids (A, B...)?