I may have found something similar:
No, stop looking for code to do what you want to do.
You are having a hard enough time just making simple changes to simple code without having to burden yourself with trying to understand what a whole lot of other code does.
Just take the code you were working on with with what I told you to do in reply #8 and post it and we can work on where you went wrong. Remember I said:-
"Try just printing the appropriate string to the serial monitor, to see if that bit is right. Then when it is change to the LCD."
So I would expect you to post your code with an output to the serial monitor which in not a million miles from the example at the end of the page string - Arduino Reference
Can I use "const char" also
Why? In your case it makes absolutely no difference. The const word just means that any attempt to change this variable will flag up an error, but you are not changing it anyway.
What sort of idiot writes this sort of thing:-
PushButton presetButtons[] = {
{2}, {3}, {4}, {5}, {6}, {7}, // ...
};