you have to make sure your clips have a linkage ID associated with them in the library. To do that, you can either right click on the library symbol or use the library menu with the symbol selected and choose linkage. Then, export for actionscript and give each the appropriate name, either “Clip1” , “Clip2” or “Clip3”. Now, when you want to add whatever one to the scene you use
where Whatload is either “Clip1” or “Clip2” or “Clip3”. The first Whatload represents which linkage id to grab from the library and the second gives the newly attached clip the instance name of whatevers in Whatload. 1 represents the depth and the _x _y are the position assignments.