How could I Apply Offsets to my Controlled

The way I like to do offsets is to add the original value of the property to the
referenced value. For example:

      thisComp.layer("Gray Solid 1").transform.position + value

If you set up your animation of the gray layer, position your other layer, and
apply this expression to its position property, you might get what you're
looking for:

delta = value - thisComp.layer("Gray Solid
1").transform.position.valueAtTime(0);
thisComp.layer("Gray Solid 1").transform.position + delta

Note that nothing will happen until you animate the gray layer.

...WoOoW, THANK YOU very much! I thought it could be simple & quick but
never imagined it'd be so much! Without any doubt this will be very usefull when
I treat to automate some movements using the puppet tool and for many other
tasks, I'm pretty sure, it'll be very welcomed too, ufff... I can imagine
hundreds...

...Hum? Something strange has happened with the other
"thisComp.layer("Gray Solid 1").transform.position + value"
solution post... Anyway, THANK YOU very much too!!! Although I'm happy knowing
the two ways, I think this last one works more in the way I had imagined,
ufff... two incredible solutions in only a few minutes, I think I can't believe
it yet :)

PS: BTW, Dan, I knew you for your "Expressioneer's Design Guide" web
page and I can't finish to write here without thank you all that incredible
contents, I LOVE it! (although I still have too much to learn as you have
seen...), GREETINGS!