attach the insertion point of a block to another block, floating base point

[rfg018]

say I have two anotation block. Block A is a line that goes from 0,0 to 0,1 and can stretch to the right.
block B is a line that goes for 0,0 to1,0 and can stretch to the north.

I insert block A at 0,0, scale 1, and insert block B at the end of block A (0,1).
If I change the drawing scale to 2, block A (the line) will be from 0,0 to 0,2 and block B (line) will be from 0,1 to 0,2.
But I want block B insertion point needs to move to the new end point of A (0,2).

I tried groups, but it did not work.

My goal is to have two or more complex block, when one changes the others will move.

Can this be done?

Thanks

[dmfrazier]

"...and insert block B at the end of block A..."
"...I want block B insertion point needs to move to the new end point of A..."
Since the endpoint of block A is always a fixed distance from its insert point, how about setting block B's insert point that same distance away (in the opposite direction) from its endpoint? (The insert point doesn't have to be "connected" to an object in the block.) This way, both blocks would be inserted at the same point. Then, when the drawing scale is changed, each block will scale the same amount from the same basepoint and the endpoints will stay connected.

[rfg018]

problem is that block may be inserted at the end of block C, D, E etc which all have different insertion point.

is their a reference point in one block that a second block could reference? and can the reference move and the second block move.

[dmfrazier]

Now you've lost me.
Maybe a visual aid would help. Could you post an example of some kind?