If I was planning to recreate the drum break in La Grange, or any other song.... for whatever reason.... I'd do it this way.

Use BB to do the music. Leave room in the song form for the break. Use a programmable drum synth to create that fill part. Put it together in a DAW.

You need to get a drum VST that would sound similar to the BB drums or perhaps use the drum synth in the entire drum part of the song.

Trying to get BB or even RB to create Frank Beard's ZZ Top drum fill will be impossible. It will never play that fill. That's why, if you're looking to get it as close as possible to the original, you will need to program it via midi. If you're not looking for perfection and just relatively close is good enough, perhaps BB/RB can generate a fill that will work.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.