1. Firstly go to the company you purchased the domain from, this could be 123-reg, Fasthosts etc.
2. Log in to your control panel so you can edit the DNS for your domain, if you are unsure of how to do this you should contact your domain registrar support directly.
3. You have to add an A record for the domain for the www and non www to point to your Kommand site which is on the IP 80.241.50.55
so you will have two entries in the DNS, one for http://www.mydomain.com and one for http://mydomain.com both pointing to IP 80.241.50.55
Note it can take 24-48hrs for this to update before you will see your website.