Manuel,
I tried something of this sort over the summer with LabVIEW 5.1 My memory isn't too clear on it but I ended up using a combination of the LabVIEW web server and Apache, which you can download for free from Apache.org
For the wml files, which can be created by any application (as they're just text) I used Apache to serve the files. After installing Apache you'll need to add WML as a MIME type. I can't seem to find the original site I referenced when doing this but here's one that might help: http://webservercompare.internet.com/wirelessapache/wirelessapache_4.html
Running two web servers can also be an issue so you will probably need to change the port you are using on either the LabVIEW or Apache web server (if you need to run both).
One other thing that I cam
e across was the service from all the wireless service providers was a factor. With some providers the WML pages would work and with others they wouldn't, something to do with the way their gateways were set up at the time I think.
Cheers,
Kamran