SD Internal VS External

[phantomodopera]

I use a lot of maps and a large database which is currently stored for offline use on the internal SD. I would Like to have this located on the external instead ( which would also allow me to swap cards for different maps/database). I assume this is actually determined by the app itself, but would anyone know of a way to change a path or something so the app would write/read on the external? I did contact the developer, but he isnt familiar with an external, only the single internal so he doesnt know how or where to change code to allow it. or maybe someone has a link that would show the developer how to reference the external?