If there's some other function needed to be added in the COM, and as time permit, I might be able to help.
I think that someone started to do this once, GlennR perhaps? But having the CURVE functions available in VBA ,without the need for the Vlax.cls & curve.cls lisp converters, would be nice. But, since I have also steered away from VBA, and AutoCAD itself is, too, I'm not sure how many would find it beneficial....I know that 3-4 years ago I would've used it a lot!
Yes.... after typing my previous response... thought the same and now that there is C#... and the PInvoke .... I guess won't be of much help