Most web programming languages that do not support Digest authentication natively can be programmed or enhanced in some way to add digest authentication. PhP 4.0, for example, can have the headers modified in the web request to add in the digest authentication.
For ColdFusion, the file that would need to modified is a local version of the following:
Simple Login cfm script
That login script would need to be modified, or the local one on your computer, to reflect the RFC 2617 standard.
I hope this points you in the right direction.
Dave Berard
Senior Product Manager, Constant Contact