Hi Alex, you can split this challenge up into three parts:
- Sample & Hold of input voltage
- Sequential switching
- (OPTIONAL) Gate length management
1 and 2 are very straightforward tasks. 3 is tricky so I’m going to ignore it for now 
Patch your pitch CV into IN and trigger into 1. Place these expressions in script #1:
X IN
When you fire a trigger, the pitch CV will be stored in variable X.
TR.TOG 1; TR.TOG 2
Trigger 1 goes high, trigger 2 goes low. And vice versa every time there’s a trigger. You’ll need to set trigger 2 high manually before this will work, or you can tuck this into your I script: TR 2 1
EVERY 2: CV 2 X
OTHER: CV 1 X
Alternating between CV output 1 and 2, set the output to stored pitch X.