Any help on this? I need some method of getting HTML data from a web address
If you mean making HTTP requests from the camera, there is not currently any known way to do this from CHDK.
It should be possible, the wifi capable cameras makes HTTP and HTTP-like requests for various things like UPnP and Canon web services, but reverse engineering would be required to figure out how to use them to make other requests. Standard-ish socket functions are also relatively easy to find, so you could theoretically roll your own or even build a third party library too, but significant work would be required to find all the stubs and understand the usage.
This thread
https://chdk.setepontos.com/index.php?topic=10724.0 contains some information about the wifi functionality.
Note if you want to control the camera or transfer data over a wifi, you can use chdkptp with PTP/IP as discussed toward the end of that thread. However, it may not be possible to shoot while PTP/IP is connected.