Relative index, or referring to a nearby cell without explicit column/row number?

I know there is a difference between relative and absolute references: if my cell A10 contains "=A8+A9" and I copy it to A20, it will become "=A18+A19". On the other hand if cell B10 contains "=B$8+B9" and I copy that to B20, it will become "=B$8+B19".

I.e. any row number starting with $ remains constant.

Now, is it also possible to express a relative row number independently of the row it's used in? I mean something like "=B(-1)" which would indicate "column B, one row above the current one" or "=C(+2)" meaning "column C, two rows below the current one".

I guess you need someting like =OFFSET()

=OFFSET(A1;2;1) returns the value in cell B3 (to rows below A1 and 1 cell to the right).