I may be wrong, but try this:

1. Setup a DNS alias with whatever name you want (<servername>) pointing to
the IP of the SPS machine.
2. Replicate Active Directory via Sites and Services
3. Go to IIS Manager on that portal box, expand web sites,
right-click-properties on the web site  that is running the portal ("default
web site" probably, if you have never changed it, otherwise whatever, just
not the "SharePoint Central administrtation") go to Web Site tab, next to IP
address click Advanced, click Add.
4. in Add/Edit Web Site Indentification, leave IP address: (All Unassigned),
port 80, Host Header value: <servername> , example - portal (not
http://portal). click OK.
5. using same method (step 4) you can also add value -
portal.yourdomain.internal (extranet)
6. iisreset

Also, visit the : SharePoint Portal server  Central Administration >
Configure Alternate Portal Access Settings
area and see what you may want to tweak there....

Thanks That was it... I dont know why i tried to do it all in
Sharepoint I should have been looking at DNS and IIS.

Create a virtual server  and register that in hosts file with your system
ipaddress.
and check that the servers are running properly and check the physical path of
that servers.