Select range till last value

[Forestq]

I have defined list to select rows from A8 to last value in column A (but before A100)

=OFFSET(sb!$A$8;0;0;COUNTA(sb!$A$8:$A$100);1)

How to do exaclty the same, but select area like: A8:C100?

When I did like:

=OFFSET(sb!$A$8;0;0;COUNTA(sb!$A$8:$C$100);1)

it's not working.

 

[Forestq]

found clue:

=OFFSET(sb!$A$8;0;0;COUNTA(sb!$A$8:$C$100);[B]3[/B])