Defining a Task to be Started with a Form 
Prerequisites
You are familiar with the procedure for
defining tasks . For this reason, a recap of only the most important steps will be provided here.You want to define the task (single or multistep task) that is to be started by the electronic form.

The part of the task definition that is relevant to forms essentially entails extending the container definition to include the elements that are to be processed as fields on your form.
Procedure
Then choose Task
® Create.Extending the Container Definition
Now extend the container of your task to include the elements that are to be filled via the form.
You can only transfer single values (not object references) from the form. If you want to add container elements for this purpose, therefore, you must always create them as single-line elements with a data type reference to a table field in the dictionary.

Since you cannot use elements that reference objects or structures or multiple line elements, you may need to make extensive changes to the container.
Further Procedure
Complete the task definition: