Well, did some testing here.
1. AviSynth can do basic resize + stack vertical and horizontal, but those are not individual playbacks. So, this is not the way to go unless someone figure how to make individual video files auto resize according to window + as individual units.
2. Using Visual C# &/or VBA here was trying to make an ActiveX & .NET enviroments in web browser style which = been good, but sadly my coding skills ends here (plus I never could remove the VLC bars so was using MPC with only window frame)
(referring
http://wiki.videolan.org/.Net_Interface_to_VLC and
http://wiki.videolan.org/ActiveX follow)
3. Found X360 Software ActiveX MultiVideo player program similar to what I'm looking for however this player only understands individual open video file where we should consider support of 20 maybe hundreds of separate video files. (
http://www.x360soft.com/products/multivideoplayer/)
4. There's also software called 'MVS Player' on their pages software states it's completely free. However, after installation first thing you'll see is serials, but skipping that part and this software is pretty close in idea however complete resize is missing and on unregistered version you only can get 3 videos when I'm talking of 20-100. (
http://www.absoftwide.com/mvs_player/)
Sad that my skills of coding simply are not enough to create stackhorizontal/vertical + resize of individual players.