>It's really not going to be generic. I would assume then in my function I would create 24 local variables, set those individually, and go on with my calculations, correct?

You can retrieve all of them in one select

SELECT
     @var1  = field1, @var2 = field2, ..., var24 = field24
  FROM ...
  WHERE pk = @PK

If calculations are simple you can do them in select as well. You can also do some partual calculations, if possible into intermidiate variables and then complete calculation using them.