controlling properties of instances in a duplicate object

Hello all
trying my firsts steps with synfing an loving the program! thnk a lot to all the developers

i am trying to control properties of instances of a duplicate layer ( i use the duplicate as Yoyobuae did in his Kynetic typography tutorial
https://www.youtube.com/watch?v=a1SBRR0EmtY)
more specific in the file i attach here i have a red rectangle in a group whit duplicate layer (0 to 5) on top and a green circle
i want to be able to change the Transformation --> Skew Angle of one or each of the instance of the red rectangle when the green circle is on the middle of the rectangle
maybe converting both origin to a aTan2 and comparing vector x and y for match and manipulation of the skew angle

my knowledge is to short to resolve it at this point so i will appreciate ideas or alternatives methods
thanks Claudio
redsquare.sifz (1.2 KB)

Firstly are you able to use the http://wiki.synfig.org/wiki/Duplicate_Layer in simple cases ? create a circle layer and fill a line of circle for example … ?

you have two tutos on duplicate :

specificly to your idea, maybe something like a mask could be used also ?
wiki.synfig.org/wiki/Doc:Basic_Masking

Thanks d.j.a.y
yes i am able to use the duplicate layer
i will see if the tutorials help me to resolve it an post here the result
Claudio