I wanted to step cyclically between one value (in a table) to another, either direction, with a bang-driven counter.

For++ steps both ways but is timed by its own delay argument.

So, lua. (I don't speak the language, but among the examples there was 'simplecounter' to rework .)

[bcounter] steps from 0 to 100 & loops back --

A float to the 2nd inlet changes the count (and starting point) to that number, resets direction of step if the destination is in the wrong direction.

A float to the 3rd inlet changes the destination, reversing the step direction if necessary.

Count -> outlet.