Auto Fill In A Subform?

Here is what I have so far. Table 1 has employee info. Table 2 is for the courses that employees take. Table 3 is a listing of available training courses. What I have done is created a form with all the employee info and linked it to table 2 by ss #'s. What I am wondering is if I can create a field, lets say course #, in table 2 and table 3. That way when I input the course number into the subform, then the corresponding info from table 3 is inserted, ie course name and course hours. Any suggestions or help would be great.