How can I download an app only appearing on the German iTunes store onto my German iPad which is registered in the U.S. iTunes store? G

Question

I am an American living in Germany, and own a German iPad.  It has the ability to connect both to WIFI and to a commercial over the air wireless network.For the latter connection, I want to use a pay by use (by the day, or by the month) account offered by ALDI, a German discount grocery store. This would be ideal for occasional use when away from home. 
My iPad is registered with the U.S. iTunes store, so that I can purchase American items such as books, movies, TV serites, etc. in English with U:S: Dollars.
However the ALDI app is not available on the U.S. iTunes store, i.e. it is only available on the German iTunes store.
I have purchased the ALDI SIM card for my iPad, but need the ALDI app in order to make it work.
Yes, I know ALDI has stores in the U.S., but they do not offer the app I need to connect to the applicable German wireless cell phone network that is based in Germany.
I need to find a way to put the German app onto my German iPad, but do not want to switch to the German iTunes store from the American iTunes store. 
I could put the SIM card in a smart phone to activate it and also to recharge it with purchased time, but would need to find a way to tell the iPad to connect to the Web via the SIM card.
I have a radio device which holds a SIM card and plugs into the USB port on my Microsoft Windows systuem laptop computer, and it works like a charm.  however, when I set it up, it downloaded software onto my laptop - or maybe only to the SIM card - not sure. To logon, when it is plugged into my laptotp, a program opens and I have to insert a password in order to activate the connection, which uses credit loaded onto the chip.
Can anybody solve this problem?

Answer 1

You cannot use other countries itunes stores.
You must be within the Country with a Valid Billing Address and Credit Card for that Country to use the iTunes Store of that Country...