HQL Sintax for Filter / Popup Select Box and Select Box Relationship

Hi Folks, i have a Select Box and need filter the information regarding the previous selection of a Popup select box  in the same form.

The questions are:

1. Can i filter the options in the Select Box (that use Default Form Option Binder) regarding a value of Popup Select Box (that use a datalist ) in the same form?
   
   Or 
2. if  i use the  Extra Filter Condition feature ?
   
   Could i  use a HQL  with a HASH variable that get the value of a Popup Select Box in the same form?
   
   

This is the scenary:

I have to choice a customer in the Popup Select Box first and later and need choice a customer contact in the second Select Box (of course both have relations from  two  tables) 

It is the Popup Select Box

If i use this sentence the Contact is filter as in need.

e.customProperties.account = 'QC0003'

but need that it work dinamically