Standard to Overtime Hours

Hello all,

I am trying to do a report showing when my employees' (~200) classifications (~10) begin accumulating overtime (OT) hours throughout the week.

I currently have the standard time (ST) returning any values under 40, however I cannot figure out how to return the OT as the hours worked once 40 has been reached. 

I think I need a formula that will return different values and a calculation, but am not sure.

I am willing to add additional cells to calculate. I need to convert it to a pivot table once calculated so I cannot have too many labels so I need the final numbers to be in the same columns in order to paste values.

Pictures and current formulas for reference: