I would like to keep the two attributes centered

on my block when stretching this shape in any of the 4 directions. I have managed to do so with the "SIZE" attribute but the REF attribute is not following suit, might anyone have some advice? 

Whilst on the topic I would like the Size attribute to alter, and feedback dimensions, each time the dynamic block is resized. What is the best way of doing this? 

I have attached screenshots for as much information as I can. 

Thanks, 

Liam