Firstly you will need a Domain Name for example: exampledomain.com
this is a regular web address

Secondlyn you will need some sort of web hosting using C Panel (beware the nhosting has to allow you to use 'Advanced DNS Zone Editor' and create Sub Domains)

next sort out the Name servers for your domain name so that the domain is linked to your Hosting and then we are ready to begin

Log into the C Panel and you will see a board like this:


Notice the Advanced DNS Zone Editor and Subdomains we need those.

Click on Sub domains and create one, this will be your server hostname. example: mc.exampledomain.com

Now go to your Advanced DNS Zone Editor and your will see a board like this:


Theren should be a listing for your new subdomain already. if there is find itn and click on edit. if there isn't already a listing use the add a nrecord facility and enter your subdomain as the name, 14400 as the TTL nand your server ip (without port number) as the address.

Once editing the entry simply change the address from your webhosts IP to your Server IP. this will redirect the traffic.
the entry should look like this:


In hope this explains it clearly enough. You should be able to use ndifferent web hosting panels however this is the one I have and the one In have managed to get working. C Panel is very common in any case.

Good Luck
B45op