Password Screen/System?

I am trying to make a traditional password screen via blueprint. I basically want the player to use a letter based system in order to spell out words that would transport the character to different stages. How would I go about making something like this function in blueprints? I already made the require sprites.

  1. Each Letter, Number and Sign has to be a Button.
  2. put all the Buttons inside a border.
  3. add a Variable to the Border - a string Array.
  4. each Buttons onClicked event should add the Button specific Sign to the string Array from 3.
  5. The OK or CONFIRM Button should take this string array, and use the Node “JoinStringArray”
  6. Use the resulting single string to compare against Words/Names/Passwords, to do different events with that.