You are clearly struggling with basic programming concepts and really should spend some time focusing on just learning the fundamentals of C/C++.
If you had those fundamentals, you'd know that char* msg and char inData[80] aren't nearly as disimilar as they appear, and that you can in fact use inData in exactly the same way you would use msg (with the one caveat that inData is, effectively a const pointer and cannot be reassigned). So there's really no point in trying to assign inData to msg (or even having a separate msg variable at all).
There's an abundance of C/C++ tutorials on the web. Trying to write code without knowing the basics is like trying to build a house without a foundation.