If CMS introduces new task types, you can probably generate some new components against them with the ASDK Task generator. Just double click the project in Symantec Manager to regenerate the library.

I've been away from this question for a long time, but I still couldn't control tasks from workflow.

I could generate the component to map with existing task in CMS, but I don't know some of its input.

There are 2 inputs, but I know only one of them, which is agent's GUID.

Could somebody guide me what is the meaning of another input? and how I could find it?

Thank you

Assuming that you are talking about workflow 7.1 the details on how to execute a task and the required params can be found in the ASDK help. The other param you are wondering about, I think it is string in XML format and its  schema is described in the help fle.