set the cell a formula looks at, based on a value in another cell?

Question

I've tried to search the forums to find an answer, but perhaps I'm searching for the wrong things as I can't get an answer to suit my needs....

I would like to be able to enter a formula, for example a simple multiplication =(C1*B5) but to be able to change one of those cells based on the value of another...

So if L3 (for example) had the value 1, then the formula would be C1 X B5 (as shown above) but if I changed the value in L3 to 2, then the formula would change to C1 X B7.....

What function do I need for this?

I've looked at INDIRECT but I don't want the value in the cell I change to directly correspond with the cell I want the formula to read... If that makes sense?

Sorry if this is a lame question... I'm relatively new...

Answer 1

so to refer to L9 when I8 is one use this simple INDEX formula:

=INDEX(L:L,I8+8)