The elusive syntax you were looking for is
Code:
With oRng.Find
.Font.Bold = True
'etc

I have to say that while your code works in Word 2013, it now doesn't work in 2007 or 2010. For those versions you would need to set the username and initials as before, with the option for 2013 (or use your old macro).
You don't really need the screen control commands in the macro.
You cannot add the highlight dialog to a userform, but you can emulate it with a group of small command buttons coloured to match the highlight colour selection. You will find ColorCop very useful when identifying colours for use in userforms.