Change player type
Note: This cheat involves editing a game file so make a backup copy of the file before going on. Then use a text editor to edit the "regions41" file in the "dat" of the game directory. Change the PLAYER_(GER/UN/CHI/JAP/SOV/NEU) to a player you like. For example, if you play as Germany change it to the following.

REGION,106,Kiev,PLAYER_SOV,Russia,TER_COLD
MOVECOST,1
POP,1
FORT,0
CONNECT,91,93,94,105,108
SIDE,6,6,6,6,6
UNIT,TAC AIR,1
UNIT,FIGHTER AIR,1
UNIT,INFANTRY,3
UNIT,MECHANIZED,1
UNIT,ARTILLERY,1
UNIT,SUPPLY,2
UNIT,RAIL,1
UNIT,FACTORY,1
UNIT,RESOURCE,3

To

REGION,106,Kiev,PLAYER_GER,Russia,TER_COLD
MOVECOST,1
POP,1
FORT,0
CONNECT,91,93,94,105,108
SIDE,6,6,6,6,6
UNIT,TAC AIR,1
UNIT,FIGHTER AIR,1
UNIT,INFANTRY,3
UNIT,MECHANIZED,1
UNIT,ARTILLERY,1
UNIT,SUPPLY,2
UNIT,RAIL,1
UNIT,FACTORY,1
UNIT,RESOURCE,3