Just to reinforce the ideas above, because that's the way I would do it, would be to have a flag variable trigger back and fourth. I do this very commonly in my experiments. Traditionally, I would use a bool (true/false variable) but Construct doesn't allow global bools. Instead, just set a variable to 0. When you need to trigger it to true, set it to 1.
For instance,
if flagVariable = 1
Players turn with instructions
at end of player turn, switch variable to 0
if flagVariable = 0
enemies turn with instructions
at end of turn, switch flag variable
You can also add in a time element to the mix, like only allow the player to move if so much time has passed.
if flagVariable = 0 && timePassed = 30 (seconds used as an example here but that can change to your needs)
It's pretty easy. I would recommend prototyping out that specific instance of the game and play with it. Try and muddle with things and when you get stuck, come back here and ask some questions. Always be prepared to give examples or code snippets of your logic to.