Hi,
1.) To show a data (time, count, temperature, etc) through your GOT, you need a numerical display with the data address you need to show (in your case D162). This means whatever is the data contained on D162, it will be seen via its numerical display on GOT.
If you want D162 be "set-able" through GOT, then you need a numerical input to do that. Example, you make D161 a numerical input & your D162 numerical display. What you want is that you write a data on D161 & show this data on D162, this is very much possible though correct programming.
Just take note that D162 is a volatile memory, meaning without power it cannot sustain data. It will be much safer to use a non-volatile memory, i.e. D1000.
2.) I have'nt done such security feature but I think its possible. I will search & advice you later.