C++ :: Change Value Of Instance Variables From Another Class?

I'm trying to change the values of some instance variables in my Controller Class so that when the user inserts values into main class it changes for Controller.

class Controller {
public:
Controller();
~Controller();
double PCFreq;
__int64 CounterStart;

[Code] ....

The user should be able to choose which foo the want to use. So I create an object of controller in main like this

Controller* con = new Controller()

Now my issues is, when I take user input (an integer) and try to do this

con->choice1 = choice1;

only the object of con's choice1 is = to user input.

However back at the class for Controller, choice1 hasn't received a value.

I can't initialize through Controllers constructor because I get the user input through a switch statement and the range of con would only be as far as the case.