So got something hanging together, bit of a fiddle.
obj-c : I had a selector that takes a parameter and then returns a value.
c++ : Looks like you can’t return a value, so you need to modify the parameter…
// Call a selector directly and give it a parameter which is return value
CCCallFuncND *callSelectorAction = CCCallFuncND::actionWithTarget(obj, sel, (void*)&retBool);
// Normally with action stuff you'd do this...
CCCallFunc *callSelectorAction = CCCallFunc::actionWithTarget( object, callback);