JBPM Customized workflow

Looking for experienced Redhat JBPM developer to provide working example on following items in JBPM workbench (WEB interface). 1. Apply filtering on custom fields (task variables or process variables) in the task inbox. 2. Adding any customized Task status (in addition to OOB) into the workbench. So i can move a task to that particular status to differentiate. 3. Adding validation to auto generated user task forms. 4. Embedding hyperlink with caseid in the user task form to navigate to another case or form within in the workbench.