Thanks for your reply. My initial question was not specific enough, didn't really say what I was trying to do.
I am using paint.net Version 4.0.13.
If I use the text tool within paint.net and put the text on a separate layer, the text appears the way that I want it to. Text Imported from the clipboard or from MS Word 2013 comes in in a white box. I am a retired cartographer and, to stay busy I will do small maps for publishers and these days most want digital (jpg) images. I can do most text within paint.net but, on occasion, I need mathematical symbols, the degree symbol, etc. (probably a dozen symbols from the extended character sets) and the fonts in paint.net do not seem to include the extended character sets. On my HP Laptop, the alt codes for the extended characters do not work; on a friends high end desk top work station, no problem.