Visio 2003 objects : linking to database

I have a table in access or excel with 3 fields: serial, name of object, and percent. I need to link it to a charting object in the visio charts stencil (pie, bar, curve bars).. to be more specific.. the % bar graph object.. it has many bars, each of which represents a % for some item.
I used the databse wizard but.. couldn’t find out what’s the name of the object property cell(in visio) that stores the % value, and seems there’s an ODBC pre-requisite that’s out of my knowledge boundaries. pls help me with a step-by-step guide on how to do it. thanx a lot.