Dimensioning Y axis - isometric view

Hello again! :)

I love this CAD.

But I still have some doubts. How do the dimensioning in perspectives on the Y axis?

 

For example:

http://ubik2005.com.sapo.pt/exe1.jpg

And i want this

http://ubik2005.com.sapo.pt/exe2.jpg

 

thanks for your help

Marcio