[Koha] queries in koha

Hi all I need some help here, Im am supposed to link koha and the main financial system of our school, i.e patrons who are students I need to either rename a field in koha called Admission Number and have it mandatory, I was thinking of using the field "Sort1" or "Initials" and have it mandatory like field "Surname" or "Zip/Postal" I have renamed it in mysql but its not renamed in koha. is this even possible in the first place? -- Dennis K. Njuguna