I don't see in the rules or scenario rules, where the Commanders of unit (UGC) and the commander in chief (CC) begin the game on the map.

Is anyone could help me ?

UGCs start with their unit groups, the CC can start stacked with any unit, as far as I remember. I think I read that in the scenario book somewhere.

That's right. The UGC's start in any hex with any of their related units while you can place the CC anywhere on the board. Preferably within command range of most UGC's.

The exact rule from the scenario book is:

UGC - Stacked with or adjacent to any of his units

CC - stacked with any unit or UGC

If you look at some of the set ups. It is necessary to place the UGC's and commanders carefully or you start with some units out of command in the first turn. Something that I fell foul of in the first game or so.

Rax