Can't the same send event step you originally used to open Adobe Reader be used to open the "wrapper"?
Can it? All I can see as options is open or print document, and he program chosen is dependent on the file associations.
Click on the filed and then pull down the Edit menu. Export field contents is specified there. But you can also write a script to do this and then put a button on your layout to perform that script. The script would be necessary to export the file to the temporary folder.