Change Font on Datasheets-Part 2

I sent an email yesterday asking how can I change a font
on a datasheet. I am working with PowerPoint 2002 SP 2.
I am working with a chart/graph in PowerPoint. When I
open the datasheet for the chart and try to highlight
just one row to make into bold font, all of the rows turn
bold. Also, there are examples of graphs next to the
names on the datasheet to determine which name goes with
which graph on the chart. I need to put the lines in a
particular order by the name, but when I do, the graph
sample next to each name does not go with it. Someone
told me that they thought that the chart/graph was
possibly created in Excel and then transferred to a
PowerPoint presentation. Is this a possibility? I did
not create this presentation, so would I need to get the
original Excel spreadsheet to be able to make the
changes? I am inexperienced in doing this, so if you can
respond to my question, could you please explain it in
easy terms. Thank you.