Printing hex digits

[meino.cramer@...]

Hi,

I have to convert *a lot* of decimal numbers, given textually in a
ASCII file into hexadecimal.

The conversion itself is not the problem ("io.write(string.format(
"%X",....))").

But the hexadecimal number have to have leading zeroes...

The format "%X" seems not to support leading zeroes as in C....

How can I accomplish this with not too much overhead with lua 5.1x ?

Thank you very much in advance for any help!
Best regards,
mcc