Deducting total from order total when matching Order#

I have two sheets in one workbook that my business uses to keep track of gold and silver product orders from our distributors and open customer orders.

(Sheet #1) "Order Sheet" --- Where we log inventory orders. When a customer places an order that we don't have in stock, it goes onto (Sheet #2) "Special Order Sheet".

Previously, the way we have been keeping track of what is remaining for an inventory order, is it to simply deduct out of it what is needed for any given number of customer orders. For example, if customer 1 on "Sheet #2" is buying 1 Gold eagle that we don't have in stock, we pull it out of Distributor 1 order on "Sheet #1". For hedging reasons (can explain if necesserary, but lets suffice it to say it's not pertinent to what I am asking), we split off the inventory in 9 Gold Eagles and add another line with the same Order # coming from the same 'Distributor 1' for 1 Gold Eagle. So, that way all 10 orders are on the "Order Sheet".

I want to build a system that will allow for us to simply plug in the Invoice # into (Sheet #2 (Column V)), pulled from a data validation list that is compiled from Invoice #s on ((Sheet #1) Column Q) and is ignoring blanks (already accomplished), and have excel automatically deduct from the remaining amount readily available for our inventory in ((Sheet #1) Column R). So, I am trying to work out the formula to place into ((Sheet 1) Column R) to accomplish this.

Hopefully this all makes sense. I've already worn my own brain out trying to explain it best I can. Thanks for any help.

If that is where it best fits. I think I just need formula help though...

I just replied to the other that I figured it out thanks.

Thanks for looking into this....

Column R is where I want the formula to be calculating what is remaining for that particular order. For instance, if we order 1000 silver rounds for our store (ie. Row 3 on the order sheet), and multiple customers come in and place separate orders each, totaling 920 (ie. rows 3,4,7,8, and 9), I want the cell in column R, on the order sheet to read as 80 remaining.
I will put values in column R of the order sheet and column V of the Special order sheet to help picture how I see this working.... open to restructuring this whole system BTW....


I will also condense the data on the sheets because they are unnecessarily long.