Hi Bill,
as far as I know there is no way to create a chart with Docs to Go. (I could be wrong, but I haven't a way to do it.)
If I were you I would either have a look at "Numbers" or use something like "CloudOn".
Numbers is an excellent spreadsheet app from Apple and with CloudOn you work in the cloud with a copy of a real Excel sheet.
Hope this helps.
Knut