[Koha] assigning books to patrons

Hi, I am working on the phase where i have to transfer library data from the old system to KOHA. I have successfully added the library books and items into KOHA using a mrc file that i created using marcedit tool Ok. now i have an excel file in which all the data related to 'which books are issued to which patron + all the due fines of the patrons' is present and i have to imnport it to KOHA. There isnt any tool in KOHA to do this thing directly. does any one has any idea how to accomplish this thing. Or moving that data directly to the database is the only option we have? in that case is there some script already available or anyone has any script that could help me? thanks a lot regards umer habib