Good question Peo!
None of the answers supplied wil do what you want, they all thought you
wanted to convert 12 to Twelve.
If you can't see it, at least in this case, it's not there! You need to go
back to the original source data. Or maybe there is a list somewhere of
whose name matches which ID, in which case you can use VLOOKUP to match a
number with the corresponding name - once you have a complete lookup table.