Date and time formatting

Greetings Everyone,

I have a situation...

In the 1st column I have date and time listed and in the second its the same except that its a different day. What i need in the 3rd column is the difference in the time in hours and minutes. How do I do it.

Example:

In the 1st column the date and time are 02/03/2008 3:35 PM and in the 2nd column it is 02/04/2008 8:07 PM. What I need in the 3rd column is the difference in hours and minutes(hh:mm format)....Help will be appreciated.

Regards

Mayank