importing an external hosted image

Hi guys
I was wondering if anybody could offer me some advice... I need to speed up my website and have been told that I need to use load movie to import an external hosted image into my site. The problem is that I need it to be in a button. I’m having problems getting it working... can anybody please either suggest how I go about this or point me in the direction of a good tutorial....

Many thanks
Jason

oh i used action script 2 in cs3 but now have cs4.

Put an empty movie clip in the button, (on it's own layer), give it a name, give the button a name and when you load the image you can target the movie clip to hold it.