Dear Sir,

   About my question,I state it by the following iterms.

   What I am doing, now :
   I use RMS(Rights Management Service) to protect the M.S Excel file.
   And I use RMS to control the print/copy/edit ... functions of the
M.S Excel file.
   Now, I want to control the rights of M.S Excel's cell.
   
   Environment :
   The version of M.S Office is MicroSoft Office 2003 (Standard)
   The O,S of RMS is Windows 2003 Server
   The O.S of RMS Client is Windows XP SP2
   I had setted the RMS Server, and I had got the lincense of the RMS
Client from MicroSoft.
   
   So,now,I can control the rights about the M.S Excel file.
   But I want to know how to control the cell of the M.S Excel.
   Example : 
             A1 cell is only used by User-A
             A2 cell is only used by User-B
             B3 cell is only used by User-C
             D4 cell is only used by User-A & User-B
             E3 cell is only used by User-A & User-B & User-C
             Other cells can't be used by anyone

             All users(User-A,B,C,D,E) must be authenticated by RMS.
  
   I want to get some suggestions for it.
   These suggestions doesn't must take a example with code, 
   but I wish these suggestions can include the following some iterms :
   a. State the flow to let me know how to protect the cell of M.S Excel 
   b. State the principle about these steps(Maybe, you can give me a
reference site to know it)
   c. Reference site
   d. Other Resource about it
  
   Limits : 
   I can only use MicroSoft C# or VB .Net to implement it.
   For some reasons, I can't use any VBA code at this case.        
   
   Thanks

Adam Hsu