registrations: how read them?

[pierino40]

I beg your pardon:
I' ve a 2100  and a 3000
the registration bank on 2100 is saved  with a file  .reg
on the 3000 with a file .rgt
Someone will explain me if I can convert rgt in reg and viceversa? and what I must do?
many thanks in advance
Piero