Yes, it is possible to do that.
There are actually two ways of achieving this:
1. you could add the .EXE as a prerequisite
to your other project
2. you could launch it through a "Launch File"
custom action. However, please note that here you can not schedule the custom action everywhere, because Windows Installer allows only one MSI-based installation to run at any given time. The setup should either be launched before the installation starts (before the "Install"
button is pressed) or after the installation ends.