For reports and fee proposals I occasionally embed drawings prepared in AutoCAD; these have been exported as *.wmf files and embedded in Word. They are 'vector' files and not 'raster /(bitmap)'. They have the advantage of being relativel'y small and because they are vector type, fonts don't develop 'jaggies' when you enlarge them.
My greater use of *.wmf files is for embedding small drawings in Delphi programs that I write. Embedded as an image, the line colours are retained and line widths are controlled using plines and setting a width.
I am unaware of any method of scaling these other than trial and error. The *.wmf file created is based on the visible display in AutoCAD. I understand that there is a commercial program/utility that allows the size of the *.wmf file to be set and I will try to dig up the name (it was posted on one of the Delphi conferences a while back).
For scaling, the kludge that I use is to include a small 'scale bar' I use on normal full sized drawings. Most of the drawings I prepare are 'D' size and these are often printed on 11x17 paper for convenience; the bar scale allows a quick method of guestimating distances/dimensions.
