Shell Programming and Scripting

I have a data in a file called SCHED which has 5 columns: sched no, date, time, place and remarks. The image is shown below.



Now, I want to display only the schedules which fall under a certain date range which the user has to input. For example the start date is 21/12/2012 and the end date is 03/01/2013, the output should then be the first 3 records because they fall under that range.

btw, i am using a dialog utility for the calendar so when i select a date, its format is automatically dd/mm/yyyy. This is how i assigned the selected date to a variable:

Code:

USERDATE=`dialog --nocancel --stdout --title "My Calendar"  --calendar "Select a date:" 0 0 -1 -1 -1`

that and the other data like sched no, time, place and remarks go to a file called SCHED.
Any idea on how I can do this? I basically have no idea on how I am going to compare the user input (start date and end date) to the dates on the file. Please help me. I am a newbie shell script programmer.

Pls use textual representation of your file and code tags for your sample. What system (HW, OS) are you on?

Can you show the actual sched file? Not a pasted image of the file? Hard to do anything without the actual raw file.