Nice of you to tell the rest how you got there, but that's no mystery
I take it you finally, at last, worked out that there's 26 letters in
the alphabet, and you did some homework on powers and bases, and learnt
there's other counting systems than the decimal system
like binary, and octal, and hexadecimal, and ...
So 'A- Z' is 1 to 26
'AA' is 27, 'AB' is 28.... (like 26 + 1, 26 + 2)
The base is 26 ....
so each letter to the left is a power of 26
so 'ABC' is
26 * 26, (26^2 * 1 ('A')),
plus 26 * 2, (26^1 * 2 ('B')),
plus 1 * 3, (26^0 * 3 ('C'))
and 'XFD' then is 16384
or Hexadecimal 4000 - nice round number, innit?
strange that - 'XFD' being the last column .....
I think most of us in this newsgroup would know the above, but took you
a while to see it, didn't it