I have labview 8.5 and Report Generation Toolkit version 1.1.2. My vi works fine during development. When I make an executable or an installer the excel vi's do not work. I have seen this question posted before but it has always been for earlier revisions and the answers do not seem to apply with 8.5 and 1.1.2.
You will have to include Dynamic VIs in the executable you build. The following link has more information: http://digital.ni.com/public.nsf/allkb/C38CE3F30542D65B86256F0E00740DD8