[Faisal_khan]

Something like this?

pawn Код:

public OnPlayerText(playerid, text[])
{
    if(strfind(text, "help", true) != -1) //returns 4 (!= -1 because -1 would be 'not found')
    {
        SendClientMessageToAll(0xFFFFFFFF, "Do /helpme!");
    }
    return 1;
}