>What is the correct syntax to do something like the following?
>
>FUNCTION GetStudentCount
>LPARAMETERS tnCourseID
>RETURN SELECT COUNT(*) FROM v_students WHERE iCourseID = tnCourseID

Here's one way

FUNCTION GetStudentCount
LPARAMETERS tnCourseID
SELECT * FROM v_students WHERE iCourseID = tnCourseID TO SCREEN NOCONSOLE
RETURN (_TALLY)

Or there is a COUNT command

FUNCTION GetStudentCount
LPARAMETERS tnCourseID
LOCAL ln_count
SELECT v_students 
COUNT TO ln_count FOR iCourseID = tnCourseID 
RETURN (ln_count)

The last one will move the record pointer to the EOF on v_students.