How to get a portion of a block to rotate about a center point

[nj1105nj]

So I have a block which contains a 2 objects, a circle with a crosshair and then a split line. I want to be able to move the line and when I do so, the line is still pointing at the center of the circle. How would I accomplish this? Is it something with a rotation command or a constraint? Thanks for any help all. 

[SLW210]

I have moved your thread to the AutoCAD Drawing Management & Output Forum.       

[CyberAngel]

Create a block with those objects. Go into the block editor. Pull up the dynamic block toolbox. Create a Rotation parameter centered on the circle. Create a Rotate action that includes the split line. Save and you're done.

Edited January 16, 2020 by CyberAngel

[BIGAL]

Try search here "dynamic rotation" there is definitely  a couple of posted block examples, one with an arrow comes to mind.

 

Found here is the block I do apologise re author I know it was a post here. I think by Lee or Steven-g.

Block dyn arrow.dwg

[steven-g]

@BIGALI don't remember it, but it could have been an answer to a post from way back. Found it, you are correct as usual it was @Lee Mac posted here at the end of last year

[nj1105nj]

14 hours ago, CyberAngel said:

Create a block with those objects. Go into the block editor. Pull up the dynamic block toolbox. Create a Rotation parameter centered on the circle. Create a Rotate action that includes the split line. Save and you're done.

I've done that but all that seems to do is create a point to rotate the line about, what am I doing wrong. Here is the file for your reference. line length example.dwg

[steven-g]

I appologise I replied to @BIGALwithout really reading your question properly. The dynamic action you require is a polar stretch this will allow you to move the split line anywhere you want including away from the crosshairs but keep it pointing at that crosshairs.

line length example.dwg

[CyberAngel]

2 hours ago, nj1105nj said:

I've done that but all that seems to do is create a point to rotate the line about, what am I doing wrong. Here is the file for your reference. line length example.dwg

 

Okay, I misunderstood the question. You want to move the split line to an arbitrary location, not a fixed distance from the center of the circle. My block-fu is not up to the challenge. Sorry.