Why not create a new template with just the boxes and a note linked to a design table. note could read $PRP@Note1, $PRP@Note2.... the design table columns would match the notes column 2 would be $PRP@Note1 and the row under it would have the text..... when you put the model in the drawing it would update automatic.
API
The notes on the sheet can definitely be found, if there is a consistant location for the notes it is even easier. Use api to search for notes, when it finds one have it check location, if its between xvalue, value1xy, and value2xy, then change note text to XXXX. There is alot more to the code than that but that would be the general idea of the program. This can be done for multiple sheets as well.