order code generator - vlookup???

Help urgently neded.

I have a pick list of text description, that when it is chosen, need to show a corresponding code reference to generate a manufacturing code.
Is EXCEL the best/easiest way to do it.
Have tried VLOOKUP function, but not sure if that is the best way
Hope the attached spreadsheet throws more light on what I am trying to achieve (if it is possible)

Thanks in advance for anybodies help

Dave