Injecting unmanaged DLL and inter-process communication

So im injecting dll to the outer process and i would like communicate/send commands to created thread. For my learning process i chose sockets as the first attempt. I have already written the server code/class. Now before making the simple client layer i have started wondering how am i suppose to pass server socket port to the compiled DLL. patch the program with asm right before injection? or there's different way out of this. Thanks for any support;)