Data input & variables - please help

Hi. I'm new to C++ and I would really appreciate if someone could help me out with a program I'm writing.  I want to write a program that needs to calculate working hours at the workplace.

1. It should print out prompt "Enter data: " and the user types in  four numbers: the hours and then minutes for clocking in followed by the hours and minutes for clocking out in the form "12 30 16 45".

2. Both input times should be converted to a total number of minutes since midnight.  E.g. 01:30 would be represented as 90 minutes.

3. Calculate result by subtracting these figures to obtain the required time interval in minutes.  This should be converted to a number of hours and minutes before printing the result in the format: "4h15" and using 24-hour clock times.

Thanks.
giggsy.