Question on formatting time > 24hrs

[Rob]

Hi there.

I want to format a field to show times which are greater
than 24hrs. In Excel, you can just put [hh]:mm to show
total hours greater than 24, but I can't get it to work in
Access (tried [hh]:nn, hhh:nn, etc.)

I can cut the total time up into a formatted text result
(using HOUR(xxx) & ":" & MINUTE(xxx) etc.) but this loses
the time value so I can't add it back together later on.
I've also tried adding TIMEVALUE('textual time') to a
formula, but this returns #ERROR (perhaps because
time>24hrs?)

Can anybody tell me if it can be done and if so, how?

Thanks in advance,

Rob