Evaluate row value as a sum of an array =< target total

[George_Martin_3]

My intention is to eventually build this into an aggregate function in order to evaluate unique demand fulfillment targets with current demanded order qty's in order to determine how many units on each can be met.

Basically have 200units intended for customer A for item A and customer A for item A has ordered 300units across 150 rows at 2units each. Assuming the orders are sorted accordingly, which quantities can be assigned partially up to the supply 200 vs demand 300?

Link to example data

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So far the only thing I've come up with successfully is a way to identify unique records matching my criteria for customer and material

(this does not match the linked data)
IF(ROWS($F$6:F6)>$E$2,"",INDEX($C$2:$C$37,AGGREGATE(15,6,(ROW($D$2:$D$37)-ROW($D$2)+1)/ISNA(MATCH($D$2:$D$37,$B$2:$B$27,0)),ROWS($F$2:F2))))

and a half finished evaluation statement

=IF($A$2:A2)<=$L$8,$H2, $L$8 - ??? SUM(ROWS($A$2:A2) -1) ???

 

[George_Martin_3]

So I've found this link that describes what I need.
Distribute Quantities of Remaining inventory across product line based on product use
I just have to translate it onto my own data and then incorporate into an array formula.