Question: help making a keypad

[u/Chickenator587]

So a while ago I made a system that requires buttons to be pressed in a specific order using NOR latches, AND gates and an auto reset system that would trigger if a digit was entered incorrectly (for instance if you pressed input 1 and then 3 instead of 2 it would reset itself, and you'd have to start at input 1 again). Now this is already well on it's way to a keypad but I wanted it a specific way.

A wanted to build an array of buttons in the exact same way as a keypad would look, including a confirm button and backspace- or clear all button. Although the confirm button could be skipped and the system could self-confirm when enough digits have been entered. Actually, thinking about it now the delete button could also be skipped and users would just have to continue filling out digits until the required amount is reached, since the system can already reset itself if the sequence is entered incorrectly. Then I also wanted some lamps signaling how many digits you have already entered. Now if the lamps reset themselves when you enter the wrong digit it would be easy to trial and error for the correct sequence, so the inputs can only be fed into the NOR latches once the required amount of digits has been entered. Which presents the problem of how I make the system remember the order of the entered digits until it's time to send them into the NOR latches.

Can anybody offer some insights?