Well, two things. "\\adddalw05\EmaHP\S04_17\index.htm" looks like a UNC path, where you're saying get file index.htm from directory S04_17 in share EmaHP on machine adddalw05. "file://adddalw05/EmaHP/S04_17/index.htm" is a relative file URL, which will look for directory adddalw05 off of the current working directory.
In any case, it looks like there are security limitations I wasn't aware of and you cannot use file URL's in app.launchURL() unless the PDF is certified by a trusted source. So, you'll need to host the file on a webserver and use the http URL to it in the app.launchURL() call.
Chris
Adobe Enterprise Developer Support