It was called "Shameless Crossover Monday." (promo pic here) (http://cdn2us.denofgeek.com/sites/denofgeekus/files/styles/article_width/public/2016/10/beckercbs.png?itok=_PpdDIre)

It was a crossover (May 3, 1999) between The King of Queens, Cosby, Everybody Loves Raymond, and Becker on CBS.

Here's a post from the television subreddit explaining this (https://www.reddit.com/r/television/comments/3btwsv/lost_episode_of_the_king_of_queens/#bottom-comments).

As well as a forum post from DVDTalk (http://forum.dvdtalk.com/archive/t-333993.html).

King of Queens -- Season 1 Episode 23 -- Where's Poppa (https://www.directv.com/tv/The-King-of-Queens-bm8vTldOZTQwV2M9/Where-s-Poppa-aXRrZ0NCRzQvUDlydmtSSE5Eekdhdz09)

Becker -- Season 1 Episode 20 -- Drive, They Said (http://www.imdb.com/title/tt0520583/)

Everybody Loves Raymond -- Season 3 Episode 23 -- Be Nice (https://www.directv.com/tv/Everybody-Loves-Raymond-WmIwSnZoNDRpWnc9/Be-Nice-WEFVRzJ2NXRlK3RtSWxJL1RzdnZudz09)

Cosby -- Season 3 Episode 23 -- The Vesey Method (http://www.imdb.com/title/tt0547208/)

Apparently, during the Becker episode, each of the characters find themselves in his waiting room, but each show features at least one other CBS character.

It appears that these crossover scenes have been cut from the syndicated versions of the shows as well as from DVD video.

This crossover seems to be very interesting and, as of now, it is really a "lost episode."

I too have been looking for information about this episode. I have a feeling it may be similar to what other TV blocks like TGIF did occasionally where there would be bonus scenes in between episodes of each show. So it's arguable that the crossover scenes are not really a part of any of the shows in particular. Either way, I am hoping someone can help us out with a copy of this episode and/or of the entire block of shows that night...