[RajatPawar]

pawn Код:

stock SendMessageToAdmins(  const message[] ) 
{
        foreach ( new i:Player)
        {
                if(pInfo[i][Admin] >= 1)
                {
                    SendClientMessage(i, COLOR_GREY, message);
                }
         }
return 1;
}

pawn Код:

public OnPlayerCommandPerformed(playerid, cmdtext[], success)
{
    new str[70];
    if ( success )
    {
       format( str, 70, "%s used '%s'.", GetName(playerid), cmdtext);
       SendMessageToAdmins( str );
    }
   return 1;
}

I don't know why this should work, just check it out. Also, you missed the 'success' parameter.