You can change the default "About FusionCharts" context menu item to show your label and link it to your own URL using:

<chart yAxisName='Sales Figure' caption='Top 5 Sales Person' numberPrefix='$' useRoundEdges='1' showAboutMenuItem='1' aboutMenuItemLabel='About My Company' aboutMenuItemLink='n-http://www.mycompany.com'>
   <set label='Alex' value='25000' />
   <set label='Mark' value='35000' />
   <set label='David' value='42300' />
   <set label='Graham' value='35300' />
   <set label='John' value='31300' />
</chart>

This results in a menu item as shown below. The link has been specified in FusionCharts link format, and n- prefix opens the link in a new window.