TestStand does not have a report engine. It takes the results of every step and creates a report by concatenating all the results and other information (including html tags) and displays it to the user using a browser.
If can also use a different report viewer to view the report. You can select the Viewer by selecting Configure - External Viewers and choose your own viewer to view the report. Further you can modify reportgen_html.seq which generates the HTML report.
You can also look at this example which displays a graph in an html report. http://zone.ni.com/devzone/devzoneweb.nsf/opendoc?openagent&83A0C6BF164CC06C8625683A000A55F3&cat=A2A6686FFD12ED3D862567C2005AB4C6
You can also go to www.zone.ni.com and click on RESOURCE LIBRARY > TESTSTAND > RESULT COLLE CTION AND REPORT MANAGEMENT To get more information about report generation.
Anand Jain Applications Engineer National Instruments http://www.ni.com/ask