Hi,
Workflow will always fire for the event defined. you cannot define conditional execution of workflow. You can create workflow and check the condition inside the workflow. The condition will be checked first and business logic will be executed only
when condition is satisfied.
You can check if Condition for the fields value comparison. Please refer below blog.
http://www.powerobjects.com/blog/2012/11/01/comparing-values-via-crmcheck-condition/
If you want to avoid the workflow execution .You can also execute the workflow using JavaScript. JavaScript will fire on change of field.In JavaScript first you can check the condition for indicator field and after that you can write the code to execute
the Workflow.
http://www.mscrmconsultant.com/2013/03/execute-workflow-using-javascript-in.html
http://social.microsoft.com/Forums/en-US/ba82a838-ccb1-4513-927a-0bf613f94514/how-to-execute-workflow-using-javascript-webresource-in-dynamics-crm-2011
Hope this helps!
Thanks!
