Hey I have a good idea to my mod, but I don't know how to make it.
Is it possible to put (almost) random videos after the skirmish/multiplayer game, but before the score screen?
I mean short videos like the famous Beach Landing video.
a GDI themed video if a GDI player wins...
...and a Nod themed one if a Nod player wins.

I doubt it's possible. You could try putting the names for the win/lose videos while making the map in the [Basic] section of the map, but I'm quite sure that the keys get just ignored in multiplayer.

I think you misunderstand me. Just imagine: there is a two player skirmish/online game, with a GDI player and a Nod one. If the GDI player wins there should be a RANDOM GDI themed video before the score screen, and BOTH players should see this. And if the Nod player wins, there should be a RANDOM Nod themed vido before the score screen, and BOTH players should see it.

jah and to prevent game crashes , how can I make this videos unskipable

Game code says Escape exits the frame looping routine, cant change that, well i can

Thats good, maybe (probably) I will need your help at some parts of the modding, however, currently I have my studyes at an informatics school, with an informatics teacher who is a bit computer nerd, and she knows about five program languages...