Ok I am just going to answer this myself since I figured it out. I'll try to be as clear as possible so people don't have to experience the same problems I had.
@SONG DATA "@MP2,127,20,0 DATA "T280 DATA "@81 DATA "@MOFCDE@MONFGAB<CThe first DATA contains the vibrato effect (@MP). Then you need to type the value of Depth, Range, Speed and Delay. It is very important that the first value (2 in this case) is directly typed after the "@MP" without spacing. Now if you are like me, you wanted to test the effect by setting everything maxed out (127). But if you set delay at 127, and your note isn't long enough, then the effect has too much delay for it to actually kick in. So if you want to try it out, set the last value to 0. The second DATA contains the tempo of the song, which is written as "T" with the desired tempo typed directly after that without spacing. The third DATA tells the program what instrument to use. It's written as "@" with the number of the instrument directly after it without spacing. The instrument codes are listed in the Smile tool. The fourth DATA contains the actual melody. Now if you don't want the first note to be modulated, you have to type @MOF before the actual notes. Later, type @MON to apply modulation to the notes you write after "@MON". If you don't type "@MOF" at the start, the modulation will be applied automatically. I would recommend the values I set here for the modulation for testing. Setting the speed to 127 can produce some nasty tunes so set these values for testing and when it works, experiment from there. I hope I can help people who have the same problem I had. If something's not clear, just ask.