.co.uk domain name help?

i’m setting up a site with web hosting, i will have a sub domain (.colmu.com). if i buy a .co.uk domain name of somewhere like godaddy will it be normal, for example normally i would go to mydomain.colmu.com/forum – it would take me to the forum if i get a .co.uk domain and i go [...] http://bit.ly/nKGjRj