First of all you are still using void main(). See my signature.
Secondly, you do realize that writing to a file is one of the most common operations you have to do in programming. Just saying you couldn't find a way to do this is extremely suspicious. What exactly have you read about and why did it not help with your problem?
1. Get rid of gets(). Never ever ever use it again. Replace it with fgets() and use that instead.
2. Get rid of void main and replace it with int main(void) and return 0 at the end of the function.
3. Get rid of conio.h and other antiquated DOS crap headers.
4. Don't cast the return value of malloc, even if you always always always make sure that stdlib.h is included.
