Is it possible to decide whether to enable/disable interactive sort at runtime?

I have a parameter for each field that lets me know if a field can be sorted or not.
What I want to be able to do is turn on or off interactive sorting for that column based on that parameters value.

In the dialog you have a check box that says enable interactive sorting.  When that is clicked it appears that you get the two arrows no matter what you put in the expression.

I have tried

=IIF(allowSorting,Fields!myColumn.Value,"")

and

=IIF(allowSorting,Fields!myColumn.Value,Nothing)

but both result in the arrows still being there, just the sort doesn't work.

Is it possible to put an expression on the sort arrows appearing at all?