How to Index a Circular Buffer at an Arbitrary Start Point?

I'm recording into a [buffer] using [recordf~] (from Percolate) with @Loop on. Now, I can read the buffer in a loop using [count~] -> [index~], but I want to be able to jump the count to an arbitrary place.

[count] takes a message ("start counting from a specific number"), but then the count-length is effected. I want to 'restart' counting from a point of my choosing.

[count] also takes a set message (i.e (set 4000)), but this has strange behavior. After 'setting' the start point, count seems to stop looping and the count length seems to be reduced.

What's the best way to playback a buffer, but be able to jump to any place in the buffer in realtime?