I started using Macrium reflect in June 2014.
Confident to backup and restore OS or partitions or folders.
Now I need to reformat my hard drive and reinstall everything so that all clutters are done away with.
There's one problem. I have a particular Program whose old version is much straight forward and user friendly.
I do not want to lose this.And I am not interested in any of  its newer versions.
A copy of this particular version is not available even in Torrents.
Is there any means to backup this particular application alone, and take it back ??

Unless you have the original installation file, it's very unlikely.
When Windows programs are installed, there are many bits and pieces put into multiple areas.

Merlin is correct but that doesn't mean you might not find some obscure piece of software on the web that says it will do it.

Acronis used to have (maybe still does but I ditched it a long time ago favoring Reflect robustness to flaky, obscure features) to backup applications. The catch was that it had to be an application that had the necessary information about it incorporated into the backup program. This allowed it to find the bits and pieces scattered over the disk and in the Registry. At the time the applications it would backup were only the very popular ones.

In your case, I think I would:
Ensure I had a current image
Clean all the unwanted stuff off the disk leaving just the OS, the application in question, Reflect and whatever else you deem essential.
Ensure the system is working as intended and if so, make a new image. This is now your base image for Windows and you can go back to this "new day 1" image at any time and still have your application available.

If you like playing around a lot and your application is not real complex whatever that means, you could:
Install a new version of your Windows (same version as on old disk) without anything else on a different disk.
Go to your old disk (the one with the application) and copy things like Program Files, Program Data (it will depend on the version of Windows and 32 or 64 bit version) how the folders are listed etc) and copy the files to the new disk.
Go into the Users Folder and look for anything that may be applicable to your application in all the sub-folders. Copy them.
Examine the Registry for any entries pertaining to your program. Copy them and insert into new registry using your favorite registry editor.
When this doesn't work, look for something you missed on the old disk such as it sticking a .dll file into .../system32 or elsewhere.

This list likely isn't exhaustive since I've never tried to do it but demonstrates the idea.

The above posts from Merlin and Seekforever give very good input on your issue.

In the good (?) old days, before the registry, it was much easier to copy programs between computers.  Most programs were self contained in a single folder, using INI files to keep all their parameters.  Anyway, it is no longer easy to do what you would like to do.

I had a (possibly) similar situation.  I had an old program that would not work with newer versions of Windows.  I use this program frequently, but NOT every day. I deleted most other programs from the system, then converted that system to a virtual machine (it ran on Win XP).  When I want to use that program I start the VMWare player and run it within Windows.  It is free. I use a version of VMWare to create the VM and use the free VMWare player to run it.

That may meet your needs.  It only takes about 15-20 seconds to start the VM and begin working with the program when I want to use it. 

I hope you are able to find a way to get your program working with your newly cleaned up system.