I'll try to explain.
Look, this is my file to go back to spanish:
Run intl.cpl
sleep 100
WinActivate RegiĂłn
sleep 100
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
SendInput, e
sleep 100
Click 257, 523
sleep 100
Click 275, 525
The automatism opens your Windows region configuration, activates the window and press the first letter of your region as many times you need to reach your country in the selection combo.
For example, If I have my region in japaneese and i want to go back to spanish, i have to press 16 times the letter "e" to reach my country in windows witch is "Español (España)"
I guess you have your Windows in English (USA) so, to calculate how many times you have to press the letter or your country, open your region menu by executing intl.cpl and the region configuration pops up:
Select Japaneese and then press the first letter of your country and count how many times you have to press the letter until reach it.
Then edit your ahk to return from japaneese to english USA and repeat the sentence "SendInput, e" as many time as you counted before.
Please, let me know if this is useful to fix your issue