I used alcohol after getting lots of tree sap on our coach. An RV park cut off low hanging branches so coach would fit under the tree. What a mistake that was,never again. Alcohol worked great.
Pine pitch/sap (and that form spruce and similar softwoods) can be softened and removed using some sort of oil-based substance. A pat of butter works nicely on one's hands, and I would think would work equally well on an RV. Of course you then have to wash the butter off, but soap and water and a bit of elbow grease should do that.