[fiki574]

Code:

stock GetOnlinePlayersCount(clan[])
{
        new count = 0;
        for(new i = 0; i < MAX_PLAYERS; i++)
            if(IsPlayerConnected(i) == 1 && IsPlayerClanMember(i, clan) == 1)
                count += 1;

        return count;
}

stock GetOnlinePlayersList(clan[])
{
        new count = GetOnlinePlayersCount(clan);
        new minfo[32], mreturn[32 * count];
        for(new i = 0; i < MAX_PLAYERS; i++)
            if(IsPlayerConnected(i) == 1 && IsPlayerClanMember(i, clan) == 1)
            {
                 format(minfo, sizeof(minfo), "%s\n", string);
                 strcat(mreturn, minfo);
            }

         return mreturn;
}

Bit shitty and unoptimized, but does what you need.