Writing array from compiled MATLAB component to OPEN Excel file?

I'd like to use the .NET interface in R2011a to write an array to an Excel workbook. The workbook will already be open so we do not want to create a new one as in the examples MATLAB provides. This is a compiled project using Builder for NE. The MATLAB component is used inside an Excel VSTO addin so we have a reference to the open workbook there. We would like to be able to pass the workbook object to the compiled MATLAB component.

From reading the documentation prior to r2011a this was not possible because there is no way to convert an Microsoft.Office.Interop.Excel.Workbook object to an MWArray, which is the argument for every compiled function. But now that MATLAB has the new .NET functionality, we're wondering how this would be implemented and believe it should be possible.

In short, the general question is how to pass in .NET objects to a MATLAB component compiled with Builder for NE so it can be used as a native .NET object in MATLAB code through the new .NET interface.

Any help GREATLY appreciated