Use this
myString = Convert::ToChar(MyVariable0);
myString += Convert::ToChar(MyVariable1);
myString += Convert::ToChar(MyVariable2);
If you get a problem with starting a string do this
myString = Convert::ToString(Convert::ToChar(MyVariable0));
myString += Convert::ToChar(MyVariable1);
myString += Convert::ToChar(MyVariaqble2);
