Determining Task Average

I've got a list of multiple users and tasks, and I need to determine the average of a particular task, and place that average next to the users performance in that task; basically, this number will appear whenever the task is listed within the row. I know I can do this by nesting an IF and AVERAGEIF function, but that would be a pretty long forumla string since we can have upwards to 30 tasks. Is there a simplier way?