Hello @Daan,
You can pretty easily use Dynamo to open up files using some simple Python
import os
def playSomething(path):
from os import startfile
startfile(path)
OUT = playSomething(IN[0])
The graph is as simple as this!
I tested with a sample from here: https://file-examples.com/index.php/sample-video-files/sample-mp4-files/