Presenting a stimulus on various sides of the screen -- Experiment Details

I am in the process of learning Superlab. I have created an experiment
that runs as follows:

Fixation appears in the center of the screen (500 ms)
Two words appear on the screen simultaneously (a neutral word and an
emotion word), one to the right of fixation and one to the left (500 ms)
A letter probe appears (R or P) and participants press the “R” key if an R
appears and the “P” key if a P appears.

I have constructed 2 stimulus lists (one for the words that appear on the
right and one for the words that appear on the left). I have coded for
word type, word position (right or left) and probe type (R or P).
Everything works great, EXCEPT . . .

I can’t figure out how to make the probe appear on the left side of the
screen on some trials and the right on others. I can physically make it
appear on the left or right, but I can’t figure out how to program the
experiment so it appears on the right for the first word pair, then on the
left for the second and third, then back on the left for the fourth, etc.

I thought about coding this feature, but the EVENT
allows you to input one position for the probe, NOT multiple positions.

If you have any suggestions I would really appreciate it! Thanks in advance!

I posted a reply to your similar question on this thread. Let me know if you have any other questions.