Split/join beam to affect one voice only

Title says it all really - on one staff in 4/4 I want the upper voice beamed in the following groups:

Upper voice: one 8th + one 16th, three 16ths, three 16ths, three 16ths, two 16ths + one 8th
Lower voice: two dotted 8ths, two dotted 8ths, one quarter.

I can force the lower voice to behave the way I choose initially but then, on grouping the upper one the lower is always affected too (and vice versa). As a new user I’ve surely missed a command - something really simple like “select voice”. However, searching here has not immediately provided a solution.

From what you describe, I guess you are trying to use click and shift-click to select a range of notes to beam together.

That doesn’t work, because it selects the notes in all the voices between those rhythmical positions.

Use click and ctrl-click to select just the first and last notes you want to beam together. That won’t affect anything in the other voice.

Thank you Rob - that was it.