I've tried several things and have not had much success getting a CFCHART to show up in powerpoint.
I'll start with my first basic approach and maybe I'm doing something obviously wrong:
<html>
<cfcontent type="application/vnd.openxmlformats-officedocument.presentationml.pr esentation">
<cfheader name="Content-Dispostion" value="attachment; file=test.pptx">
<head>
<title>Test</title>
</head>
<body>
<cfchart format="png" title="Basic Chart">
<cfchartseries type="bar">
<cfchartdata item="2007" value=50>
<cfchartdata item="2008" value=70>
</cfchartseries>
</cfchart>
</body>
</html>