First welcome to theSwamp Mark!
The Thumbnailer.arx was done by Tony Tanzillo, and I'm not sure if he updated it for '08 or not. Did you find the older version? If so, does it not work in '08? I use it, but am only on '06 for now. If one knows C# (or vb .Net) then they could write there own, but for now all I know is of Tony's.
To save a drawing the way you want, I would use a script file. I would use a lisp to write the script file. I think there have been some posted on here that will write the script file (opening and closing parts) and all you tell it is the middle part.