I live in Dali and have hiked Cang Shan several times, and just went to Huadianba for the first time last week. Look up the article on this website by the foreigner who runs Hikedali (search for 'huadianba') He doesn't mention being able to climb up out of Huadianba towards the south - which is the direction that you're asking about (the direction of the Cang Shan peaks and the Black & Yellow Dragon Pools and TV tower). I also didn't see any trails heading that direction when I went - and Google Earth - of some usefulness in this situation - didn't show any that I can make out either. (You are checking this out on Google Earth, I hope)
For the path to Huadianba, follow the article's instructions; head towards the top of the water pipe. Again, Google Earth should give you a good clue how to proceed. You'll have to check in at a fire prevention shed, and then wind your way through tombs and then up a dirt road. Ask locals, also.
If you want to head up to Black and Yellow Dragon pools, then that's a separate hike from a different starting point. Getting a service (hikedali, or the one mentioned earlier on this page) to take you up isn't a bad idea, especially if your time is limited.
The gondola up near the Horse Washing Pond is up and running, but they usually won't let people who came up via the Gondola out to explore the mountain. You have to stay inside the Gondola station. Alas, you have to hike up in order to be able to summit.
In 2011, a young man who wasn't prepared for injury and the cold died on Cang Shan. Best of Luck! Stay Safe, and be prepared for emergencies. I'm sure you'll have fun.