What I was trying to accomplish was being able to run the android adobe reader and selecting a file to open that doesn't have a .pdf extension. With a windows version I can select "All Files (*.*)", but I can't figure out how to do this with the android adobe reader.
However, I have found a solution....
I put the pdf file with the modified extension in the download directory of my android device. When I want to view this file, I use an android file explorer (I use ASTRO) to change the file extension to ".pdf", then I open android adobe reader and the file appears in the Documents download folder list. When I want to hide the fact that it is a pdf file, I use ASTRO to rename the file. It is a bit cumbersome but it accomplishes adding another layer of security to the file which is also password protected.
If you can tell me how to have the android adobe reader show me all files, not just pdf files, that would be a more convenient solution.
Thanks,
tularosakid