Yet, I've not found out if it is possible to change the default input language via a shortcut or if it's possible to disable the regular fall back to the default input language when opening a new program, but I've found an alternative!
Googling the problem, I came across the following article written by Androgen Belkin:
http://www.script-coding.info/AutoHotkey/AhkRussianEng.html
He explains that Russians always have a similar problem with their keyboards concerning the Russian and English language. Thus, he created a script that checks and switches on user input, if necessary, the default input language when Windows starts. The script can be found on the above link at the very bottom and has been written for AutoHotKey, a free keyboard macro program. Luckily, I am a devoted AutoHotKey user myself.
Instead of Russian and English, I adapted the script to check for the German and English default input language. It works errorless and is very handy because now I can set my default input language with ease :)
Furthermore, AutoHotKey supports compiling scripts into single executables. I don't want to withhold my script from everybody to whom it is as useful as to me.
Switching default input language [Germany (German) <> English (United States)]:
http://www.megaupload.com/?d=A8HKEV4A
Filename: Switching_default_input_language_DE-EN.zip
Contents: (1) Switching_default_input_language.ahk (AutoHotKey script; for editing or re-compiling the script), (2) Switching_default_input_language.exe (stand-alone executable)
Have fun! :)
With Microsoft Keyboard Layout Creator you can create CTRL+ALT+ combinations, here is how:
- Go to: File -> Load Existing Keyboard...
- Select "Shift states" (left) and click the wanted button on the keyboard, and then paste the mark you want to be createn when that key combination is pressed.
- Go to: Project -> Test Keyboard Layout... and test if everything is ok.
- Go to: Project -> Build DLL and Setup Package. wait until it asks to open the folder and then run the Setup.exe it created for you.
- Open Control Panel -> Regional and Language options (icon) -> Languages (tab) -> Details (button)
- Select the keyboard layout you installed from the "Default input language" (list)
- Press Apply and look for that little keyboard icon at your taskbar right side (possibly), click it and select your custom keyboard layout. Now it should work.
Note: I'm not sure about the last (three) steps, but I was able to make it work only after clicking that keyboard icon and selecting the layout from there.
May be the most simple solution is KeyTweak. There's also Microsoft Keyboard Layout Creator but it's an old program and not easy to use as much as the one I suggest you.
KeyTweak download
Both are presented there: Remapping the Keyboard Layout in Windows XP, Vista, and 7
How to Remapping the Keyboard Layout in Windows XP, Vista, and 7
Best Answer
Windows 8 (or 10) allows you to add the touch keyboard button to the taskbar. Simply right-click the taskbar and select "Show touch keyboard button". You can then control the keyboard with the mouse, using the same long press as you described for a phone keyboard. This keyboard allows access to Œ through O and Æ through A. It also has additional keyboards of emoji, etc.