It's posible to save and load data to the cluipboard via datatypes library,and I have the simples case working fine. SketchBlock now supports copying and pasteing layers via the clipboard.
Using DTST_CLIPBOARD as source type with NewDatatypeObject allows loading from any clipboard unit. I think I have that working too.
To write to the clipboard you need the DTM_CopY method as faras I can tell. I can't see a way of specifying unit for this.
Anyone know how?