To set this you would navigate to your Newforma Administration console, (you must be a Newforma Global Administrator to complete this action).  Now navigate to the Servers Tab.  Select you Info Exchange server and go to the General tab below.

Select the Browse button and navigate to the location of your image file.  This image can sit anywhere on your network or even on your local system.  After you select this image, Newforma will place this image file in the correct location so it will resolve on your Info Exchange server and in your Newforma Template forms.