SAVE AS *.PDF OPTIONS

Hello,

I'm preparing an application for saving a PDF file from a drawing.

I've written this code and works:

retval = Modelo.SaveAs4(NuevoNombre, 0, swSaveAsOptions_Silent, 0,0)

The problem is I have more than 1 sheet and always saves all thesheets in 1 PDF file.
Does anybody know how to save only the active sheet?

Thanks.SolidworksApi macros