Hi there, I have been trying to use Custom dlls and they work work fine while used in the report directly, ex: add reference to the dll in the report and the create an expression using this dll later on in the report, this works just fine. Here is my question, How can I use a custom dll in a shared datasets?, let me explain it better.I want to create a shared dataset and set as a filter the result from a function inside of the dll, Ex: I have various customer from different divisions, they are allow to render and create reports bases on the divisions that they belongs to. (one customer could be in more than one division), when they come to the reporting services I take the userID and then make a query to the database and grab the divisions for this user and then use those divisions as a filter in a shared dataset. That way I don't have to ask the to pass the divisions as parameters and they don't have to add the reference to the custom dll every time that they want create a report, just use the shared dataset and Go!. The problem with this way is the shared datasest does not know about the custom dll, and if I set and expression like this: = CustomDll.MyClass.GetDivisions(User!UserID) in the filter for the dataset, I will get an error, "The filterValue expression for the shared dataset contains an error [] Name 'CustomDll' is not declared" Does anybody knows one way to use those custom dll in a shared dataset expression? Thanks in advance. I will keep myself trying different way, I will post the results if any. Peter