can't access \\computername or http:\\computername but able to access \\xxx.yyy.aaa.bbb or http:\\xxx.yyy.aaa.bbb

I am trying to access that IP or computer name from my 'Corporate LAN' which is windows 7 clinet. and the //computername or http:\\computername is windows server 2008 r2. a standalone server but not joined to 'corporate lan'

How to resolve computer name.

Any help??

Thanks

Neeraj