Create an assembly to decrypt data in SSRS 2008 R2

Hi Forum,

How can i create an assembly to decrypt data in SSRS 2008 R2.
I have encryted data in an Employee table and i need to be able to decreyt the data to print unencrypted values.
I am envrypting the data using a certificate. I can decryt the data in SQL but i want to be able to decrypt it in SSRS.
I am using the following code in SQL.

CREATE SYMMETRIC KEY Emp
WITH ALGORITHM = AES_256
ENCRYPTION BY CERTIFICATE EmpCert;
GO

OPEN SYMMETRIC KEY Emp
DECRYPTION BY CERTIFICATE EmpCert;
GO

What need is a funtion to open the Symmetric key and a function or assembly to decrypt the variables i need to print on the report.
I am using ALGORITHM AES_256 as you can see above, where i create the Certificate.

Any help will be greatly appreciated...

Regards,

Manuel Roman