Hmm.. looks like you really new to programming.
"main()" as you say is the entry point for the program you write. Syntactically and technically you cant write anything outside main except macros, function definations and declarations, and global variables.
So if you want to write "cin" outside main create your own function and then write cin anywhere in that function you want.
By the way, what are you trying to achieve? IF you are a complete newcomer to prog then try out the sticky or thread "Starting C" which will help you out in getting some programming concpets cleared. Also look at these sites.
http://www.cprogramming.com/tutorial/lesson1.html
http://www.cplusplus.com/doc/tutorial/