Rent Collection Program (Crystal)

Hi. We have a project for a Crystal programmer. Our company has a program to collect rent, and we need several changes implemented to the program. Although we don't have the source code, we have the program in Crystal and we also have the database in Access. We are not sure if it is possible to change the program without the source code, but are open to offers and ideas. Please let us know if you can do this and we can get in touch with more information.