Duplicates Processing

All,

I've been provided a CSV file of parts that contains duplicates of
properties (e.g. resistors have a wattage, tolerance, and temperature
coefficient property) of those parts that differ by a manufacturer
part number. What I'd like to do is to process this file and, upon
encountering one of the duplicates, take that part with its new part
number and move it to a part substitutes table. It seems like it
should be pretty simple, but I can't seem to generate a query or a
function to accomplish it. I'd greatly appreciate any insight or
assistance with solving this problem. Thank you very much in advance.

-- Gary Chambers