TMS Software TAdvStringGrid : searching on several columns (multiple key)

Hi,

I need to find a record which key is a combination of two columns.

For example :

col 1      col2     value

A            A             5

A            B             7

and so on...

I wish I could do a Locate() but there is no dataset behind.

I read carefully the SmartBear sample that is provided with the software but... did not found anything.

Any help would be much appreciated...