AutoCad :: Make Block To Automate Design Of Typical Cross-bracing Connection Plates

Attached is a small scale sketch that I'm trying to work with.

Drawing3.dwg

I want to make a block to automate the design of typical cross-bracing connection plates relative to the angle of the x-brace. Since the angle varies from one structure to another, I need a quick way to draw these.

Make a dynamic block that would locate to the intersection of the beam and the x-brace. Then I'd adjust a "rotating reference line" from the block to align with the x-brace and then offset the plate edge to mate with the beam web. Sounds easy, but...

The parts that I need dynamic are:
1) the edge of the plate that mates to the beam web (since different beams have differing web thicknesses - this needs to be adjustable).
2) the edge of the beam flange (to make the line type hidden below the beam flange)
3) the rotation of the reference line to align with the cross brace line (so the holes are properly aligned)

I was originally trying to achieve this with a rotate parameter, but had no luck. So I just thought of replacing the rotate parameter with a polar stretch parameter and it's the closest I've been to resolving the problem, but there's still a funny quirk. When I align the reference line in the block to the cross brace angle, the two other adjustments (web and flange locators) rotate too and become skewed. How can I keep those other two beam adjustments horizontal?