Is there any changes I could do to my cycle so that I can make it move backwards?Just a question out of eagerness.
To sum up all the comment answers, which provide you with a wealth of options:
Some parts of these look rather easy to fabricate such as the idler arms or connecting two forks together. The rear hub is going to be the most difficult part since you have to build two sets of engagement together and fit it in the space of a regular hub.
A British gentleman by the name of Drew Buck actually rode the 2007 Paris-Brest-Paris (a mere 770 miles (approx.) in 90 hours) on a 2-speed 1913 Hirondelle, with a low gear engaged by pedalling backwards in the Retro-Direct style.
There's a nice article by Kent Peterson on a retro-direct bicycle
Just to actually answer the question, even though it's not as interesting as some of the comments: yes, you can probably convert your bike to a fixed gear, and then if you can learn to steer backwards and not fall over, you will be able to pedal it backwards.
There are several questions about fixed gear conversions, here's a starting point: Planning on building a fixed-gear/single-speed from an old Schwinn World. What new parts will I need?