Ecxel is a dynamic program, desiged to always update graphs and formula's as new data is entered. In order to copy a 'picture' format of the graph, you have to go around Excel.
If you select the graph, copy it, open a new word document, paste the graph (still linked to an internal sheet copied with the graph). Copy this graph in Word and paste it back in your Excel sheet. This will remove all dynamics and treat it as a picture.
Nils Bevaart