How to connect UDL file to a Msaccess DB 2007 (Protected with password)?
I found to ways to solve this problem. 
First, I have opened the 'UDL' file using a text editor and change it as follows :

[oledb]
; Everything after this line is an OLE DB initstring
Provider=Microsoft.ACE.OLEDB.12.0;
Data Source='Your_DB_Full_Name';
Persist Security Info=False;
Jet OLEDB:Database Password='Your_Database_Password'


Second, I have viewed the UDL file properties (mouse right click) then:


At the Provider, tab select the driver.
At the All tab, double click on the Data Source property and write the full name of your DB (with full path).
At the all tab, double click on Jet OLEDB:Database Password property and write your DB password.
At the All tab, double click on the User ID property and write your DB user if it was different from Admin.
Finally, click OK.