“the page cannot be displayed” when accessing over network

I’ve installed wordpress 2.2 on a server 2003 system and have integrated it into a custom build php based intranet solution.
When accessing the blog via the Intranet link on the local server (which has apache, php, and mysql installed) the wordpress blog page will appear.

When accessing the same site via the network I get a “page cannot be displayed” error
The link in question is https://msisyds2:99/blog/wp-admin/post-new.php

When accessing the https://192.168.70.23:99/blog link from the local server I get a nicely formatted ‘hello world’ welcome page.

When accessing the https://192.168.70.23:99/blog link over the network I get a rather rudimentory “hello world” welcome page.

I am new to all this wordpress/blogging concept, so I wouldn’t know where to start with all of this.

Your help would be appreciated.