To: meleyre
Dear user,
You can place the video file on audio timeline in AVS Video Editor and use it as audio track, while video can be changed or editted (you can add another video instead, add video/image overlay and use the video track partially).
Please follow the link below to find the detailed instructions on how to edit video in AVS Video Editor:
http://onlinehelp.avs4you.com/AVS-Video-Editor/index.aspx
Let me know if I can be of any further assistance to you.
Kind regards