In the future having the ability to attach a property from a reference object to a point would be very valuable. I'm not sure if anything like that is available in the API currently. if it was I'd still need to find time to get back into dot net to find a final solution.
You can do that, if you have lots of time and want to learn .NET. The ability to extend Autocad has always been one of its key strengths over other solutions like Bentley or Carlson, which are far weaker in this regard. But if you bill yourself out at more than $10 an hour, I can pretty much guarantee you'll spend more in lost time coming up with your own routine than you'd spend purchasing the third-party product mentioned earlier. Not to mention, the third-party product gives you several other powerful tools in addition to this one. And with your own solution, you'll also get locked into upgrading it every year before you can move up to the latest version of C3D. So unless you really want to learn programming, or unless you have no paying work and are looking for something to do, it isn't a cost-effective use of your time.
I've noticed there's two distinct personalities among C3D users. There's one set of people who view C3D as a "challenge", and like to find ways to force it into submission, even if the solution takes a long time to do, or is very elaborate, time-consuming, or difficult, because of the self-satisfaction that comes from out-thinking the software. Then there's the people who like to get their work done quickly and easily. Third-party solutions like the Sincpac-C3D are for this second group.
