Passing Variables to Loaded Swf

Hoping someone can help me here,

i have a swf file that i am loading into a parent movie and i need to pass some variables to the loaded movie, unfortunately i do not have the original fla file of the movie being loaded in so i cannot use _root or _global ect…

the swf that is being loaded in works fine and originally intended to have the variables passed though flashvars, is there any way i can pass these variables though the parent without having to change the fla of the loaded in swf

hopefully this all makes sense
thanks in advance