Microsoft Excel has a built in ROMAN Function that will convert arabic numbers to their Roman Numeral equivalents.
The output is text based and not number based.
In my example I have a list of numbers in column A starting with 1 and going to 24. In cell B1 type the following Function:
Then simply pull this function down until you reach row 24. You should then have the arabic numbers displayed in column A and their Roman numeral equivalents in column B. Quick and easy!!
I wish I knew about this when I was learning Roman Numerals at school!!