Impossible on being dumb?

Hello! 🙂

Maybe im attempting something impossible or Im being relly dumb?

I got this table where I check my stock levels, the second table is the desired result. (Last column is the one with the formula giving me problems):

• The Stock Required will be used based on the JobSartDate
• When Stock its used, the Qtyafterall stock will be use for the next job 
• When a new OrderQty arrives(OPDueDate) This is added to the Stocklevels

The problem I have is when the OP arrives, its added on all the rows where the JobDate>OPDate as it thinks they are different OP nums, when in fack is only one.

Is any way I can modify the formula so the OrderQty is only added on the dates is due? and when its added then its not added again later?

=IF(H1=[@MStockCode],IF([@[JOB StartDate]]>[@[OP DueDate]],((I1-[@Required])+[@OrderQty]),I1-[@Required]),([@QtyOnHand]-[@Required]))

I hope this makes sense

Thank you