Calculate net income minus retirement contribution based on if ret amt > 0 and then subtract net wage - ret amt and place in net wage in cell overwriting previous net wage amount

ret amt = retirement amout

net wage column for employees

ret amt if only user getting ret. contributions

then I need to subtract net wage = ret amt and place in net wage cell with net wage - ret amt or net wage if no ret amt to subtract.

new to calc. I have been reading but not finding.

Because a formula can not replace a value in another cell you will not find a solution. Usually you need a third column:
Netwage, netamt, netwagecorrected
The other option would be a macro to be run only once (if netwage still contains a formula) wich replaces netwage-column with the corrected value. But you loose the formula by doing this.

will be sufficient in both cases, as subtracting 0 will cause no harm.

I managed to get the following to work. It needs a safer condition and messy for troubleshooting. I’ll work on these but it returns the required values.
Thank you for helping; the references are relative so it works down the column. T hold retirement amounts; F-P hold the Fed/State tax items.

=IF(T10=0,ROUNDDOWN(+F10-G10-H10-I10-J10-K10-M10-O10-P10,2) ,(ROUNDDOWN(+F10-G10-H10-I10-J10-K10-M10-O10-P10,2))-T10)

=ROUNDDOWN(F10 - SUM( G10:K10 ; M10 ; O10:P10 ) ; 2 ) - T10