In that case yes.
I've never had good video quality (and by "never good" I mean it was beyond unacceptable) with my easyCAP. But yeah, you can get that audio adapter and use it. That ~.5 second delay I mentioned still applies, unless your computer is gonna handle it differently than mine (and I've seen it over a few different motherboards and audio chipsets).
Anyway, yeah, you'd run that adapter to your Line-In (or Mic, if you don't have Line-In), then in Windows sound options (right click the speaker in the system tray > Recording Options) right click Line-In > Properties > Listen > check "Listen to this device" and set Playback through this device to whatever sound adapter you want to use, then click apply and OK and OK.