Formula Help Please!

I have been trying to figure this out for days! I am very much a beginner with formulas, so frustrating!

I have a report that is grouped by employee numbers (each employee has a distinct number).
I want to figure out what their net monthly salary is including their auto earnings (phone, rent, car, etc.).
Not all employees receive auto earnings, some employees receive multiple auto earnings.

I cannot figure out the formula to show an employees auto earnings or show $0 if there are none.

I've tried:
if {AE.EarnCode} <=105 then {AE.RateAmt} else 0

It's just listing all the different auto earning rate amounts in the report.

If I try:
if {AE.Employee} {AE.EarnCode} then {AE.RateAmt} else 0
it tells me I need a boolean, which I don't want, I just need it to tell me how much the employee makes in auto earnings per month. I've figured out the salary which was easy for some reason but the auto earnings are throwing me for a loop!
Thank you in advance for any assistance!

So are there multiple auto earnings per month per employee? If so, you may need to set up what we call a manual running total.  Basically by using a variable, you check in the details if you have a auto earning and  add it to your running total, at the end of the details, then you can use that variable to be used in another calculation or displayed.

You need to take the first formula you created and Sum it, which you can do by inserting a summary on the report. You'll need to sum it for the employee number group. Then place it in either the group header or footer.

-Dell