Hi Paul
You may want to consider embedding your Excel charts in your Word document. You can then edit/update/change them inside MS Woprd by simply clicking on the chart and Excel will open with the document. Once you have finished updating the chart in excel simply click outside of the chart to close the excel editor.
The only downside to this may be the eventual size of the file depending on how much data is in each of the 21 charts.
However it is worth considering this approach.
Good luck.
Tony(OTPM)