Converting exe to DLL

I have a windows executable that I'm trying to convert to a DLL.

Right now it uses cout and cin to get the user input. There are a bunch of functions in the executable. I'm new to programming and never written a DLL. From what I've figured out, I need to adjust the following:

First, remove the input and output code from the DLL. The DLL is being passed a string from a ColdFusion application.

Next, I think the following references will need to be replaced:
ofstream scrn. cout, cin,scrn.open("stdout",ios: ut), scrn<< , scrn.close(), and exit(1).

Does this sound correct?

Thanks

James