Precache an URL Soundfile

Is there a way to precache an URL Soundfile? (.wav / .mp3 / … whatever)

I doubt it could be done in garrysmod. However I did find this.

call sound.PlayURL and don’t play it?

It’s streamed so it doesn’t get downloaded all at once AFAIK. Which means doing this won’t actually do anything.

How would I use this in Garry’s Mod?

DHTML panel, make it run the PlaySound() JScript function on initiation.