Load Var. XML to query string

I am trying to load a flv file on a server into a flv player. Right now it is pulling the flv via xml from a file i found on the interwebs.

I’m new and confused as to how I might be able to do this via a query string.

I am guessing LoadVar or loadMovie…then a swf. then the query; my.swf?=“query”

I know what it has to do, I just don’t know exactly how to “say” it.