[Jefff]

Yes it possible

pawn Код:

GetNearPlayer(playerid)
{
    new Float:X,Float:Y,Float:Z;
    GetPlayerPos(playerid, X, Y, Z);

    for(new i=0; i != MAX_PLAYERS; i++) // loop
        if(IsPlayerConnected(i) && i != playerid && IsPlayerStreamedIn(playerid, i)) // checking connected streamed players for Me
            if(IsPlayerInRangeOfPoint(i, SetRangeHere, X, Y, Z)) // if player is in range of Me
                return i; // return victim id

    return INVALID_PLAYER_ID; // if none is in range of Me return invalid id
}

public OnPlayerKeyStateChange(playerid, newkeys, oldkeys)
{
    if(newkeys & KEY_YES) // key 'Y'
    {
        new victim = GetNearPlayer(playerid);
        if(victim != INVALID_PLAYER_ID) // we found a victim
        {
            SetPlayerHealth(victim, 100.0); // sets victim 100 HP
            return 0;
        }
    }
    return 1;
}