Here is how I do it:
1. In Revit your Solar Study setting in the Sun Settings must be set on "Still" on the specific 3D-view that's open in Enscape. Here you also choose the date.
2. In Enscape you'll have to create a new view after changing the sun position you want in Enscape (I think it's not possible to save the sun position after creating a new view)
If anybody has a better workflow, please let me know