He is saying(I think)

If Cell L2 is 5 Then

Cell B2 would contain the following formula:

=Sum(B2:F2)

Cell C2 would contain the following formula:

=Sum(C2:G2)

etc etc

If Cell L2 is 3 Then

Cell B2 would contain the following formula:

=Sum(B2:D2)

Cell C2 would contain the following formula:

=Sum(C2:E2)

etc etc

Hope this helps you martindwilson,

Dan