Unwanted Date Conversion - Please Help

Hello, I have a report that is based on a dynamic column. The column is specified by the user, and the column tyep may be text, datetime, or bigint. The user specifies the column name, and there is also a parameter that specifies the type. I allow my users to format the date via passing in a date format string, so my code looks something like:



=Switch

(

Parameters!primarycolumntype.Value = "text",

Fields(Parameters!primaryitemcolumn.Value).Value,

Parameters!primarycolumntype.Value = "date",

[DO DATE FUNCTIONS HERE, e.g. Year(Fields(Parameters!primaryitemcolumn.Value).Value)],

Parameters!primarycolumntype.Value = "numeric",

Fields(Parameters!primaryitemcolumn.Value).Value

)



The trouble I am running into is that I am getting invalid date conversion errors whenever a text value is being supplied - in other words, the code in the "DO DATE FUNCTIONS HERE" is being executed regardless of whether my primary column type parameter is text OR date. It would appear that all conversion fuctions are calculated at runtime prior to running other logic. If so, this is a bad thing for me, as that means I cannot mix data types in the same report and figure it out all dynamically. Is this true? I had always thought that the date code (in the example above, the call to Year()) would not be executed unless that statement in the switch statement was true. I've had the same luck with If statements, and Choose statements, and I've even tried using custom code.



I think my whole problem relates to a misunderstanding of how the functions are processed. Can anyone shed some light?



Thanks!



Michael