Control Stream Coding

Greetings All! I have a study in which two drugs were administered. Drug A was given at a fixed dose and is the drug that I have PK data for and am modeling. One of the covariates that I would like to look at is Drug B, given at either dose X, Y or Z (3 options). Does anyone have any suggestions on how to enter this into the csv file and then how to subsequently write it into the control stream? Thanks tremendously for any help that can be provided! Best Regards, Susan Susan Hudachek, M.S., Ph.D. Animal Cancer Center Veterinary Teaching Hospital Colorado State University 300 West Drake Road Fort Collins, CO 80523-1620 PHONE: (970) 219-7599 FAX: (970) 297-1254 EMAIL: [email protected]