Fill Datagridview intercalating data from 2 queries

I have a Datagridview, It will have pairs of lines:
first line: requested customer
second line: assigned quantity for that item for that customer

Something like:
CUSTOMER-ITEM-VARIATION1-VARIATION2-VARIATION3-VARIATION4
Cust001....-120.-......10........-.........0.......-........8........-.........1
Cust001....-120.-........0........-.........0.......-........0........-.........0
Cust002....-120.-......15........-.........7.......-........2........-.........0
Cust002....-120.-........6........-.........0.......-........1........-.........0

The second line will have numbers if other table has information about that customer reservations, or will be in 0 if not.

I can load the first line of each pair, with the data of the "requested" items loading a datagrid with a datatable.
The problem is that i don't know how to add the second line.
Thanks!
And sorry if something is hard to understand, english is not my first languaje.

Sorry for the bump, first and last time...I'm stuck with this =/
thanks!

Pretty hard to do, unless you load each row by hand.

Why not have two grids. When they click on a record on top, the detail records show up on the bottom?