Instantiating class query

Hi,

I'm fairly new to oop and I would like to create a movieclip instance that I attach to the stage dynamically as there will be several of these attached to the stage. However, each movieclip will load in some text dynamically from a text file. There will be several text files for each movieclip. I thought it would be best to create a class to handle this. My question is when I instanstiate the class (presumably this will happen when I attach an instance of the movieclip to the stage in the code) how do I pass a variable to the class?

Thanks