Help making a "quantity updater" macro

Hey guys, if working on a small project right now, and i'm a bit lost.
here is what i need to do.

Column A= Item
Column B= Quantity In-Stock
Column C= Quantity Subtracted

i need a macro that would take "column C" subtract it from "column B", and then clear "column C". if the macro could do all the rows simultaneously, as apposed to having a macro for each row that would be great.

thanx for all the help in advance.

Correct me if I'm wrong, but wouldn't you want it updated line by line?

For example...

I change C25 to say I took 3 of whatever stock. I would want that subtracted from B25 straight away, otherwise how would person B know I've taken those 3 stock?

Essentially, you could do a On_Update macro to check if column C has been changed, and then update the cell in B.

I'm sure there's a more elegant way to do it, but it's quitting time, and I've got to go home.

Private Sub Worksheet_Change(ByVal Target As Range)
If (Target.Column) = "3" Then
Cells(Target.Row, 2).Value = Cells(Target.Row, 2) - Cells(Target.Row, 3)
Target.ClearContents
Exit Sub
End If
End Sub

-Bob

Hi,

Sorry I should have mentioned that the code I wrote goes into the sheet (Microsoft Excel Objects, not modules) code, as it would form part of the worksheet.

For something to be button based, it would need to search column C for non blank values, and then subtract them from B. Without using a loop (line-by-line evaluation) to check "If Is Not Blank" I think the only way I know how to do it is with a "Find"

This should do what you're looking for. Again, not the most elegant in the universe, but it worked for me. Replace "Sheet1" with your sheetname.

Sub FindSubtract()
With Worksheets("Sheet1").Range("C:C")
    Set C = .Find("*", LookIn:=xlFormulas)
    If Not C Is Nothing Then 'Found value
        firstaddress = C.Address
            Do
                Cells(C.Row, 2).Value = Cells(C.Row, 2) - Cells(C.Row, 3)
                Set C = .FindNext(C)
            Loop While Not C Is Nothing And C.Address <> firstaddress 'If it's not the first instance, keep going
    End If
    Range("C:C").ClearContents
End With
End Sub

Thank You so much "Beeawwb" for all your help, worked like a charm.