How do I send message between windows?

Here is what I want to do:
1. execute an execution file, phoneBook.exe, which was written in VB 6.0 from a window which was created by VC++
2. phoneBook.exe shows a phone book dialog which allows user to select a phone number. After the selection, it will notify the calling window and pass back the phone Number user selected .

my questions are how do I:
1. notify the calling window that the job is completed
2. pass the phone number back to VC++ window?

Thanks in advance.
Tiffany Chen

I'd write the VB application as an ActiveX exe. That way you can use it as a stand-alone application and still use it via automation from another app (your VC app).
You could write a public class module with a public property like

public property get PhoneNumber() as string
' show modal dialog for selecting phone number
PhoneNumber = selectedPhoneNumber
end property




It should be fairly easy to use the VB app for automation in your VC app, because you can import the type library.