Best way to Duplicate Enemies

Hi guys! I posted about a month ago about a Helicopter arcade shooter game i was making. I have kinda stopped making it but now want to start it up again. The reason i gave up last time around was because i couldnt get the movie clip of the enemy to duplicate itself without problems. What is the best way to do this? All of the actionscript for the enemy choppers is contained within the movie clip. It seems like now that i had everything working and as soon as I added in the duplication of the movie clips i opened a pandoras box cause problems started sprouting up left and right. The duplicated helicopter uses the same random numbers as the first so it does everything like the movie clip its copied from. What is the best way to duplicate enemies with flash (5)? Thanks!