[Script] I need help to understand and eventually create a script to assign value to a custom field

Hi all.

Here is my problem.

For some incidents or requests, i want a more tuned system of prioritizing. We have already a formula to do that, but now i need to apply that formula into the SDP.

The formula consist in set 5 fields (pick up list) with 4 to 5 values possibles in each one. This values, have correlation with a numeric value. For example, Field A has Option AB, BB, CB, and DB. AB is equal to 1, BB to 2, CB to 3 and DB to 4.

We name the values in a way that any technician can understand the meaning, but, for our formula, we need that value to have a specific weight expressed in a number.

The script that I need, has to do the conversion of the alphabetic values, to its number, and then perform a simple equation (multiply the values) in a new file, which we call "Score".

My knowledge of Python or general programming, are minimum to null. So, can i do this in the Script section on the Form And Rules option?

May i have some help from anybody?

Thanks in advance.

Best Regards.

Facundo