Well, I have been doing a little searching and Louise Mandrell is the key to finding this episode. She was on Hee Haw quite a bit. Anyway, looks like it's possibly on Season 21, episode 17. They play one new Hee Haw on RFD-TV per week and they appear to be in order (my folks had a lot of episodes on the DVR). Anyway, at this rate, it will probably be about 5 years before they air it *sigh* Looks like there are 24 seasons of Hee Haw. Yowza!
There is an episode guide on TV.com.