From an interface, is it possible to link to a report and pass it a parameter to filter the report for the user based on a process variable that is grabbed from the form.

Reports don't have processes associated with them when they're accessed from the Reports tab, but if you make it the action, you can use the interface rule for a UI task in the process model and pass in whatever data through PVs or ACPs that way.

Thanks, I was hoping to call the report from an interface. So, in general, any report is just static? There is no way to pass it some sort of input parameter then.

Reports can be dynamic after they are loaded. forum.appian.com/.../SAIL_Tutorial.html
so you could have the user enter some value, and then dynamically show different components based on that.