Ours is enterprise edition . i need to know how to create a custom report. i can see the link to "Add new Report". but it is asking for xml to upload . i need to know the format of the xml to upload.

My requirement is to create top 10 employees based upon workflow completed and time. For each and every action in workflow we have assigned maximum/expected time to complete the task. so the top the report of 10 employees will be based upon Total Completed task and time taken . i need to check whether the user completed the task within the time limit mentioned in the Action.

Can you please guide me how to create a custom report or what is the format of an xml to query this information.?