Four On The Tree?

I am asking about a column shifted
4-speed for my 1970 Belvedere.
If I had a separate lever on reverse popping
up through the floor, or something,
could I hook up the 4 forward speeds to the
column? I’ve never looked at a column shift
setup, so deferring to your brilliance.

If you think about it, the OEM Chrysler
column shifter is a 2-plane deal, a simple
“H” pattern. And, starting in the ’60s sometime,
the “external” (hanging below column)
rod was replaced by a much more
precise concentric (tubular) deal.
I think re-engineering the column into
a 3-plane shifter would be a gargantuan
task (think: space shuttle, etc.) One thing
that might work, though: Use the existing
3+R column setup to shift the four forward
speeds, then a beefy solenoid (and maybe
return spring) for reverse. Since the interlock
is built into the side cover of an A833,
you’d not have to worry about erroneous
shifts into reverse while any forward gear
was selected (and the opposite).
As you inferred, a separate reverse-only
manual lever (floor mounted) could also
work, but then you’re kind of negating the
“sleeper” effect you’re looking for.