Try Sleeping's formatting trick again, Bus and type the format as such:
Select all cells involved in input and results, then click Format > Cells (or CTL + 1) and click Custom then in the Type Box enter:
[hhhh]:mm then click OK.
hhhh works up to 4 digits, naturally - type more if you need above 9999 hours.
Highlight the desired results cell then goto the Formula bar and type an
= sign then highlight your high value cell then enter in the Formula bar the
- sign then highlight your low cell value then hit the enter key.
Worked here on Excel 2002 XP and Excel 2000. Note: Ignore Excel's reference in the fx bar to strange dates when data input cells are selected - happens anytime we use colon(s) with numbers.
W.R. has it right, I would only add all MS Office Apps are all ar$es in that they often give us the illusion of flexibility and ease of use but......
You can always record the hours and minutes in their own cells and with some creative
cyphering applied, you may have the desired results at hand....