I am a service engineer, and i'm looking to use excel to manage my stock better

I have tried a few things and it's all manually input/edited

I would like to know if it's possibale to use VB, to auto manage these levels
IE, 1 box asks for the part number
2nd asks you how many
3rd/4th boxes are "+", "-"

When + or - is pressed the part number will automatically add's/subtracts
that part level.

Say.. I had 10x abcde's I enter 2 in "How Many", then press "-" it will then
adjust the level from 10 to 8

My excel sheet would have parts in it
Col1------Col2------Col 3
Part No---Desc------Qty
ABCDE----Bits-------10

Can any one please help

Thanks in advise for anyones help

Tony