Either use a 4 measure introduction with repeats at either end or make the intro 8 measures long (you might need to add extra spaces in to create this).
If you use IN to indicate the intro, then use A (meaning section A) for the beginning of the song (so it knows when the intro stops, and for the player to know where to go back to if you repeat the song a few times).

There is additional information that might be helpful in our glossary:
http://www.irealb.com/forums/showthr...&p=282#post282

For some songs where you the introduction is the last 4 or 8 measures at the end of the song, you can hold on the measure you need to start from and play from there. (Make sure your chorus count is set to greater than 1 otherwise it will just play from there then end.)