I think you're a bit confused as to what a proxy is actually doing. The anonymouse proxy will not help you reach your local server from the Internet.
What you actually need to do is:
first create a static route on your router to redirect all incoming connections on port 80 to your local server. Something like (hypothetical setting interface)
WAN IP: *.*.*.*
wAN PORT: 80
LAN IP: <your machine ip>
LAN PORT: 80 (or the port you're running Apache2 under)
But that alone won't be enough. Why is that? Because if you're like 99% of people out there, you are being assigned a dynamic IP address. You can check your IP address via websites (such as http://www.whatismyip.com/) or your router status page.
What it means is that you would be able to access your server using the IP address UNTIL the IP is being updated for various reason, including but not limited to: router reboot, IP lease renewal from your ISP...
Of course you could try to secure a static IP for your router, but it's typically
- difficult (depending on your ISP)
- expensive (since it's a custom service)
A static IP would allow you to access your server via your public IP address.
However, I suppose you don't want to have to remember a cumbersome IP address, which brings the next point: domain name and DNS.
DNS are servers that provide mappings between domain names (ex: superuser.com) and the IP addresses that the machines actually use to communicate and resolve the traffic.
First, you would need to register a domain name somewhere. There are plenty of registrars everywhere, just google a bit and you'll soon find more than you'll ever need.
Second, you need to configure the mapping to your static IP. Also DNS entries take some time to propagate, so even after setup, you might need to wait between 30minutes to several hours before your domain name is correctly assigned to your IP address.
HOWEVER, static IPs are, as I said earlier, hard to come by. Your best bet might be to use a Dynamic DNS service (ex. http://dyn.com/dns/, commercial service) which allows to use dynamically assigned IP addresses. Most routers come with support for this specific dynamic dns service.
With this, each time your router updates it's IP address, it notifies the dynamic dns service and updates its record. Therefore your domain name is always mapped to the latest IP address.
All in all, it's a lot of effort and cost for something like this. It all depends on what you're trying to do (temporary hack, long term solution, ...)
In my opinion, you might be better off renting a virtual server somewhere on the cloud (Amazon, Rackspace, SoftLayer, ...)