in the image:
"a","b","c" are objects
"a" should have anchored properties of "b" and "c" ("b" radius + "c" length)
Anchor Properties Set Data to properties of others objects.
Explain in greater detail. I don't see anything at all about rectangle "a" that could possibly be the result of the radius of circle "b" and the length of [poly?]line "c". It looks like you mean the total length of "a" should be the sum of the radius of "b" and the length of "c", but it's clearly a lot more than that. Is it something about "a" other than its length that should relate to "b" and "c"?
And by "anchored" do you mean that if something about "b" and/or "c" changes, "a" should change accordingly? Change in what way? Should its proportions remain the same, but its size change? Should one dimension of it stay the same and the other change? Etc., etc.
Kent Cooper, AIA 
I mean something like Field and Attribute Definitions, but with Property Set Definitions.
with next Property Sets:
what I wish anchor any object, included ACAD objects, and use Anchor Property Set
Something like this:
