IIS won't serve outside Workstation

How do I configure IIS so that it can serve pages even outside our local
workgroup? I know for a fact that if your web server named
"myWebServer" is a member of a workgroup named
"ourWorkGroup" and another computer named "myWorkstation1"
is also a member of "ourWorkGroup", published pages can be requested
by "myWorkstation1" by using
http://myWebServer/<virtualdirectory>. Now, we also have a domain
controlled network (lets call this "theirDomain") that is physically,
part of the same local area network. I can be sure of this because I can browse
network shares from "ourWorkGroup", say, a share from
"myWorkstation1" by using this UNC \\myWorkstation1\SharedFolder from
a computer in "theirDomain" However, when requesting pages from
"myWebServer"  using http://myWebServer/<virtualdirectory>, IE
displays a "Page cannot be found" error page.  Is there something I'm
missing?

There's nothing you can do on IIS for this, it's a networking issue, probably
because the domain can't resolve the name of "myWebServer".  Does it
work if you use the IP address of myWebServer in the URL?

Also check firewalls and other securoty software on your network.

Jeff

Thanks for replying guys. 

I've tried that before. Instead of using http://myWebServer, I tried to use
something like http://192.168.77.3 but still it can't load the page.

The ip of the machine where I'm trying to access the page is 199.99.99.5. My
colleague suggested that I should make this machine (with ip 199.99.99.5) a
"member" of  the group of myWebServer by supplying it with another ip
similar to that of myWebServer.

Here's what I did (with the machine with ip 199.99.99.5):

1. Right click My Network Places, select Properties

2. Right click Local Area Connection, select Properties

3. In the window Local area Connection Properties, I selected Internet Protocol
(TCP/IP) & clicked Properties

4. In the window Internet Protocol (TCP/IP) Properties, I clicked Advanced.

5. Under IP addresses, I added 192.168.77.200

4. Under Default gateways, I added 192.168.77.1 (same gateway with myWebServer)

After doing above steps, I tried browing http://myWebServer, still nothing.

But when I tried http://192.168.77.3, It worked!

I should be happy that it worked but I'm having doubts. Is this really the case?
I mean, is there any more elegant solution than this?

Thanks for taking time reading this...

It's all basic networking.  Address translation, firewalls, private address
space, logical networks based upon ranges and netmasks...

None of it is IIS.

Jeff