How do I make a program with two arguments in dos

one for a filename to read from the other for a filename to write to?

Look up what arguments the main() function accepts.

int main ( int argc, char *argv[] )
the first argument is the filename of the exe
// We assume argv[1] is a filename to open
FILE *file = fopen( argv[1], "r" );

what about the second filename and how do I copy the contents of the first into it regardless of the file type?

Here ... read THIS

No, really... you need to actually read it, instead of just looking for code to copy.

Ok I got it.
Thanks