For Reader there are three methods (I know of) for passing data, that don't require special rights or something else. None of these use the IAC, which doesn't work with Reader.
I don't know if any of these methods are compatible with Angular.
1. Submit to a server script. The script can be local.
2. Acquire local file data with "util.readFileIntoStream".
3. Use the Acrobat open parameters to specify an FDF file, which was presumably just created by the app.
#1 and #2 are driven from the Acrobat side. Only #3 is driven from the external app, which is what I think you intended.
Hope this helps.