The Morph++ package must be installed in the same runtime folder as V4.2.  Both V4.2 and Morph++ pack can be installed in any external runtime. 

A dummy folder is just a folder to contain your uninstalled folders.  Just create a folder called temp runtime.  For V4.2 and the Morph Pack to install correctly to the dummy folder, create a dummy Poser.exe with a text editor program and place it within the temp runtime folder.