Add to browse for folder

I have seen all the posts about how to browse for folders/computers.
They almost do what I want to do (browse for a folder on another computer).
My problem is that some computers on my LAN are not listed in Network Neighbourhood.
They can only be located by typing the name in the open dialog box (e.g. \\roule\) or in the Explorer address bar.
Is it possible to add a field to the browse for folders dialog to access these 'hidden' computers?
Something like a text box where the name could be entered and then be passed as the path?

Any help gratefully received as I haven't used the API much at all.

/Andrew