You can do that easily. The 2nd dialog is opened by calling DoModal()
] but before calling this function you can assign values to any public member variables in the 2nd Dialog class.
Let's assume the 2nd Dialog has "firstmarameter" and "another parameter" as member variables. We can assume the first Dialog also has a member variable named 'data', so you can see how to assign values from one dialog to another:
Dlg.firstparameter = data; // assign a value from the 1st dialog to the 2nd
Dlg.anotherparameter = "This is my new dialog";
// assign a value to the 2nd dialog
Dlg.DoModal(); // Launch the 2nd dialog