Hi Youssef,
Only two numbers can be setup this way in CUE, the users Primary DN and the number entered in the E.164 slot (you can use this for a Mobile or other number that you frequently use to access CUE;
Place one ext in the primary ext field, and the other in the E.164 field
phonenumber - Specifies a number or extension for this user. No spaces or dashes are allowed.
phonenumberE164 - Specifies a telephone number with area code for this user. No spaces or dashes are allowed.
Example:
se-10-0-0-0(config)# username user3 create
se-10-0-0-0(config)# username user3 phonenumber 50180
se-10-0-0-0(config)# username user3 phonenumberE164 13335550180
From this good doc;
http://www.cisco.com/en/US/products/sw/voicesw/ps5520/products_administration_guide_chapter09186a00803ef7a7.html
Hope this helps!
Rob
