For starters, one post would asffice - three is over the top.
It's easier to put the router back the way it was unless you can lay your hands on a Cyrillic keyboard. the A and M are the same in both alphabets but for the D, I and N you need to make changes. Even then, theree's no guarantee the word will be the right one.
Go into All Programmes>Accessibility>System Tools>Character Map and change the Character Set to Windows Cyrillic then copy the characters д и and н.
They are the D, I and N in lower case Russian so write out the whole word with "aдmин" and see if you get away with it. Frankly, I have my doubts.