My brother is an alcoholic bipolar chain-smoker, off his meds because of a dependence on the booze for sleep and a conflict there with the mood stabilizers. He has a daughter and a wife. It's a long process. Addiction is fucking terrible, it sneaks up on you and makes little problems like missing a pill or an appointment so much psychologically worse by circumstance.
First step is that he has to recognize it's going to hurt his kid if he keeps going - even if he doesn't think he's going to keep going. Obviously he will, but the first bit is more important. If you haven't, talk to
him about his daughter. This is about him. Just lay your concerns out on the table. If that doesn't work, try to rally support with his ex or any nearby relatives, but for the love of dogs don't break up his family. A good start is not insinuating that this will break up his family, to him
or his ex. That can and will destroy people, and it's completely unnecessary - he does not have to hit rock-bottom to break out of this, that's a romantic tragedy that I wish I could gut Hollywood for popularizing.
Something a lot of addicts, and drug users in general, do not understand at the time of their abuse is that help is available to them. Not resistance. Help. Even going to the police,
walking into the police station and asking for help for your drug problem, in most jurisdictions you are likely to be given a number to call for anonymous support rather than thrown against a car door and handcuffed. This is because almost every police officer has an understanding of why these specific drugs are a problem, and rather than going footsoldier against every last addict subjected to meth wheedlers, they're much more concerned with the dealers. YMMV - I'd suggest the support groups first, because there are some seriously bad cops.
So, knowing that, there's no reason not to get support. Making it clear that there's no judgement involved, that
he has the problem with meth/crack (was under impression that crack = cocaine, not sure if this is a difference in local vernacular) and not you, will help tremendously. He's probably insecure because he knows there's a problem, and is looking to shift blame on you for 'not supporting him' - a cry for help indeed, but with a shield up. A neutral third party will be easiest for him to cope with to start out.
Of course, convincing him that help is available is where the challenge is. Not knowing him, I have no idea how to do this. My only suggestion is to make sure to listen. Good luck!
~Internet advice
Edit: I realized I gave you no practical resources, which is a perpetual problem for this kind of situation
http://www.recovery.org/ this is a good place to start. If you don't find anything there that seems like a good fit, I would personally talk to local rehab clinics yourself about the situation, ask them if they have initial support services that they recommend or work closely with, and go from there.
Make sure you don't make the same mistake I did, and give your friend the contacts you make so that if necessary he can pursue them by himself.