Quick question anyone can answer, on variable named MCs

How can I specify differnt movie clipnames with a variable increment.

For example I want
the my_FLVPlybk name to increment like this: my_FLVPlybk1, my_FLVPlybk2, my_FLVPlybk3, my_FLVPlybk.

But off course this doe snot work:

var num = 1;
my_FLVPlybk + num.contentPath =

How can I do this?

Ron