Depending on what you want to do this could be rather easy, or quite involved.
The easy way would be to either accept a different field name at first, insert all the parameters in the fields you want to use, and then open the EESchema source files with a text editor and to replace all instances of the field-name you want to change.
This however only works once, if you want to run the script after you have changed the field names, you should first rename the field-names to the original names.
The more difficult approach would of course be to add support for a new field-name. If it is just one or two reasonable new fields, I might even take the time to add it myself.