That's something that the SWF that plays the FLV will need to take care of. So, as you seem to have already suspected, this is something to take care of on the Flash side, not the After Effects side.
Many thanks for this.
So, if I import the fiash file I created in AE into Adobe Flash, how would I go about setting it to autoplay?
> So, if I import the fiash file I created in AE into Adobe Flash, how would I go about setting it to autoplay?
I'll leave the Flash questions to the Flash folks. There are a few that hang out here on the After Effects forum, but I'd bet that you'd get better answers faster on the Flash forum:
Autoplay is a Flashvar (= parameter) to any SWF object you embed into a HTML page. The code e.g. Dreamweaver generates takes al lcare of that. All you need to worry about is to eitehr contain the FLV in a SWF or find a suitable player skin.