Copy Task workflow

Hi all,

we have a requirement that user should be able to copy his tasks.

So I added a button on the ribbon which is triggering an on-demand workflow. (https://ribbonworkbench.uservoice.com/knowledgebase/articles/132235-create-a-workflow-short-cut-ribbon-button-no-code  was very helpful)

However I don't know currently how to copy attributes from the old task to a new task in this workflow :(

Can someone help me?

Thank you,