@erfajo This trick works well indeed 
@d.kelfkens I did not manage to read a specific cell with ReadExcel.ByRange (I can not make it work anymore, I don’t know why) but I was looking for a solution to make the graph wait until I give an additional input and I succeeded with Springs.Filter.BySelection just before the passthrough, because it generates a popup. This could be a first workaround.
Here could be another solution for a popup but I did not try it yet: