[web2py] Need some help with a simple case of routing

[Cliff]

In my application, "localhost:8000" should go to the welcome app.  
Any request with a subdomain, such as "dc.localhost:8000" should go to the 
operations app.

I try this, but it raises syntax errors at startup:
routes_in = (
    ("localhost:8000", '/welcome'),
    ('.*\.localhost:8000', '/operations')
)
routes_out = (
   ('/welcome', r"//localhost:8000"),
   ('/operations', '.*\.localhost:8000')
)

Traceback (most recent call last):
  File "web2py.py", line 16, in <module>
    import gluon.widget
  File "/media/Myfiles/3-o/gluon/widget.py", line 23, in <module>
    import main
  File "/media/Myfiles/3-o/gluon/main.py", line 114, in <module>
    rewrite.load()
  File "/media/Myfiles/3-o/gluon/rewrite.py", line 274, in load
    p[sym].append(compile_regex(k, v))
  File "/media/Myfiles/3-o/gluon/rewrite.py", line 361, in compile_regex
    raise SyntaxError, "routes pattern syntax error: path needs leading '/' 
[%s]" % k0
SyntaxError: routes pattern syntax error: path needs leading '/' 
[//localhost:8000]

What am I doing wrong?

Thanks,
Cliff Kachinske