This is much easier said then done and there are multiple different types of captive portals out there, we could not possibly support them all. Besides, this would be a clear violation to their ToS:
- Prohibited Uses
You specifically agree not to:
access (or attempt to access) the Comcast Web Services through any automated means (including use of scripts or web crawlers), except through APIs or other interfaces specifically provided for this purpose, or violate the instructions set out in any robots.txt or similar file present within the Comcast Web Services;
attempt to or actually circumvent any method used by Comcast to control access to Comcast Web Services, including, but not limited to, spoofing or otherwise impersonating an IP address for your computer that is not actually assigned to your computer or setting up a proxy or other device that allows others to access the Comcast Web Services through it.