Hi,
First of all, you might want to check class cl_bcs for sending emails. Basically your function will do the same but this class is a bit more functionality. Plenty of examples in SCN/Internet.
Whatever function/method you will choose to use, the idea is to develop a workflow method, and then call the email sending function/method from this method. Then you of course develop a task that will call your new method. Now, you will need certain parameters for the email sending function/method: subject, body text, recipient, etc. You need to either deliver these parameters for the method from your workflow container or build some additional logic to the workflow method. E.g. if your task TS01000140 gets the email text into the workflow container, then you need to bind it to your email sending task (and to the method) => you need to add this to your task container and then add it as a parameter to your method.
One additional hint: When building the custom logic, pay attention to email language. You want to deliver the emails in correct language, so the recipient language must be known before the email is sent...
Regards,
Karri