Slight problem with stacked notes of different durations.

I'm transcribing from a score based on a piece from Alexandre Guilmant and I'm having a problem trying to enter the following measure:

Problem: If I try and dot one of the minims(halves), both get dotted. It seems I can't dot one without dotting both of them?
Am I missing a way of telling Notion that certain notes are for certain players?

Problem: If I try and dot one of the minims(halves), both get dotted. It seems I can't dot one without dotting both of them?
Am I missing a way of telling Notion that certain notes are for certain players?