Greetings fellow humans and others,
Firstly, I am a noob so please type your responses slowly and use generous spaces.
I have created a custom payload ('payload.exe', using msfvenom, hyperion and a C compiler) and it does work on it's own, getting through and calling back (when using VirtualBox). However, I can't find a way to attach it to a crafted PDF ('clickme.pdf'). All my efforts have failed, in that the payload (once attached using msfvenom again), can be detected by Av's. Any assistance/guidance would be appreciated; but do not delay. This setback has delayed my dastardly plans to take over the world and my cat is getting grumpy. (She's the kind that sits on your lap and looks away disapprovingly when disappointed...)
A big thank you to Gingerbread Man for his suggestion to post this question.