Xander,
Maybe I should explain more about the python script listed above.
I have a set of parcels with different attributes that need to be updated weekly. The engineer has an excel sheet, that I initially generated from the attribute table, that he updates various fields for each parcel of land. To uniquely identify each land parcel, I have to match up two attributes. What the python script does is, see if the two attributes match up, then use an update cursor to change the fields.
I use a CSV file since I get an excel file each week and just save it as a CSV and run it from there. Now, I do not know enough about python and other such things to make it more efficient but this works for me. I am not sure if it would be speedier to take the excel table to a geodatabase each time versus just a CSV since it's normally about 200 records.
So, what I'm saying is, this exact script would not necessarily work for the OP but it's similar to what I use for having to match up two fields (without creating a new field that concatenates the other two, etc.). I hope that makes sense.