Data summarizing!?

I use a software that generates reports in excel(These reports fill up Columns ("A:DG"). I have to clean up the reports every month and submit them. I am trying to make this process quicker.

So I created a application that when activated removes all unwanted columns and sorts the corrects columns by either a Part number or a vendor (via userforum).

I want to be able to summarize the information by the part number.

So in Column ("A") I have a many of the same part number and in Column( "B") I have the quantity of that part number. Looks like this

Part Number---------Quantity
AAA123--------------------10
AAA123--------------------25
AAA123--------------------40
AAA123--------------------30
AAA123--------------------20
AAA123--------------------75
BBB345--------------------10
BBB345--------------------25
BBB345--------------------40
BBB345--------------------30
BBB345--------------------20
BBB345--------------------75


I want it to look like this:

AAA123--------------------200
BBB345--------------------200



The generated report can have anywhere from 1-10,000 parts... Any help??