[Konstantinos]

Actually he can with a loop.
Define a variable and in the command /givemespeed set the variable to 1;
Example:

pawn Код:

new CJ_Speed[ MAX_PLAYERS ];

pawn Код:

public OnGameModeInit( )
{
    for( new i = 0; i < MAX_PLAYERS; i ++ )
    {
        if( CJ_Speed[ i ] == 1 ) UsePlayerPedAnims( );
    }
    return 1;
}

pawn Код:

public OnPlayerConnect( playerid )
{
    CJ_Speed[ playerid ] = 0;
    return 1;
}

pawn Код:

CMD:givemespeed( playerid, params[ ] )
{
    CJ_Speed[ playerid ] = 1;
    return 1;
}