One way:

=IF(INDIRECT("S" & M1)<8, INDIRECT("S" &
M2)+8.5/24+F28/24,NOW()-TODAY()+F28/24)

(where your values are in M1, M2)
Tim

"Leon" wrote in message
...
I have the following formula:
=IF(S5<8,S4+8.5/24+F28/24,NOW()-TODAY()+F28/24)

I need to replace the "4" in "S4" and the "5" in "S5" by a value stored in
an other cell.
I tried some variations of "Match" and "Index" but it doesn't seem to
work.
Any help or pointer will be gratefully appreciated