After interest has been shown, I recompiled the dwgCrawler so that it will work for AutoCAD2009 and also AutoCAD2012, 64bit. They are available at ncadaddons.tumpliner.com.
I checked into further versions of AutoCAD and decided not to go that route because I am essentially a 2D user of AutoCAD, and I can see no further value for 2D use in later revisions beyond 2012. Also, the API changed after 2012. Changing the API, so that programs compiled for earlier revisions will need to be recompiled, gets a little annoying, especially when there is no real value gained for 2D work. So that is another thing I like about NanoCAD. I compiled it once, and I do not have to recompile it each year or every other year. They are not coming out with changes to the API, and I think they value the customization programmers enough that they will not break the API to require recompilation for little or no reason. They do not have the motivation to get people to upgrade every year-- they are not charging for the software. They only take a cut from the action if a developer is selling an add-on for use with NanoCAD.