Please turn off the CAPS Lock, more than two lines would
be extremely difficult to read. Reading caps is annoying.
Format the column as text, if the leading zero is important to
you then it is an identification not a number. The default
alignment for text is left aligned which is also better for
most identification "numbers".
Credit card numbers are 16 digits, are identification and
can not be entered as numbers, ever, because Excel only
retains 15 significant digits.
Identification "numbers" are seldom used arithmetically,
except perhaps to create check digits, but that can usually
be done with strings anyway.