Create a file named player.ini in your Syberia folder with the contents:
800 600 16 0 BaseCMO.cmo
The only value you should ever edit in the ini is the 4th integer (0=windowed mode, 1=full-screen mode). The first three values (Horizontal resolution, vertical resolution, bit depth) are hardcoded so they will be ignored anyway, the last one (name of the main game file) should be left alone.
For Syberia 2, the contents of player.ini should be
Once again, 0=windowed mode, 1=full-screen mode, leave the second parameter alone.