Support to model instead of base plate

I'm using Cura for a slicer. Custom supports are nice but I have situations where I'd like to have support from an overhang to a spot on the model--not all the way down to the base plate.Cura doesn't seem to have that option, so I'm thinking I add a support to the model itself. But, I don't know the tricks to make the support break-away easily, like the supports Cura adds.Can someone point me to a resource on how to design a support for an 90 degree overhang, in the model, not down to the baseplate, but to a nearby vertical surface? Examples are the red shaded areas in the attachment that don't have the support blockers added. Especially the overhang in the top right corner. I'd like the base of the support to be on the vertical surface, not all the way down to the bottom of the model.