I post here this link with an example using pdfcreator 2.4.0 com interface

this example print 2 reports in one PDF file 

before run the example install pdfcreator 2.4.0

I suggest using command line

pdfcreator-2_4_0-setup /Silent

and restart your machine before run the example

https://drive.google.com/file/d/0B6CfTLgUpUXgTXNGajRaY0FTNzA/view?usp=sharing

Regards.