Format Text Styles issue...DWG wont save changes

I have a freelance designer who uses the "other" CAD program. He sends the DWG file to me with a font that I don't have. I know how to correct it and make it one I do have. HOWEVER, I have to do this every time I open that file to edit it. I cannot make the DWG retain the changes. EVERY time I open the file, I have to make the same changes to the text style in order to even READ the text entities.

 

My process is: FORMAT- TEXT STYLES - TEXT (choose appropriate text name, edit to font on my machine) APPLY - OK

 

This makes the font read correct on the drawing. The problem is when I close the DWG and open it again later. I have to repeat the process.

Am I doing it wrong? It's making me crazy!!

 

(any help would be appreciated)