A thingy me jig

[ukracer]

Internal hex grub screw
Allen key which is a good fit into it to suit
Turn / Grind point on allen key
Cut off to length
Insert into set screw hex with a dab of araldite / Loctite
That leaves you with an external hex (Smaller than thread Dia) to get hold of, with a point on it for transferring the hole

HTH
Dom

Got any pics I cant quite see what you describe mate??

 

[cr500dom]

Havent got a picture but this is the same thing knocked up in Solidworks
Grub screw, section of allen key turned to a point, stick one inside the other and you have an easily removable transfer screw !

I was trying to come up with a solution I could make easily on a modelmakers lathe, as I have an engine - gearbox adaptor plate to make, and you cant get in there accurately enough to mark out.

Hope that helps
Cheers
Dom