Store Inventory

I have a poor inventory management system. I need an actual count of my store. I have a scanner and here is what I want to accomplish:
I have a data download from my database. It will include the item database name, cost, retail, the items custom barcode, and the POS names we have given it.
I will scan and count each item in my store on one page.
I need to cross-reference the count sheet vs the data sheet.
I want to be able to identify a total value of my inventory and also start to update the POS database based on what products we actually have