Can install app in external storage but set by default internal

Hello,

I have a problem with basic4android. The cuestion is the next:

If I set "install to internal storage" I can't move the app to external storage and if I set "can install to external storage" the app is installed to external storage by default.

I want set that the app "can install to external storage" and the app is being installed by default to internal. Is possible to do it with basic4android?

Sorry for my English and thanks a lot!