multi row reports

multi row reports

Hi, I need to create a plain report to export a spreadsheet. 

I have a Form A for "Headers" that contains a Subform that lookups "Detail" info from Form B.

So users can create a Header record and assign as many rows from B as needed.

When I run the report I get

Header Field  Detail Field
------------  ------------
A             B1, B2, B3

I need this output:

Header Field Detail Field
------------ ------------
A            B1
A            B2
A            B3

Is it possible ?

Thanks !