Put user interaction in UIActivityViewController process

I have a problem. I want to send some data as exce or csv or pdf. Stream, I have to present UIActivityViewController. I have to click on the email button. Then the activity controller should disappear. Then a view (made by me) will come up asking about the format of the file I should send. This will then open a mail viewer with an email address and so on. I will click the "Submit" button and it will be sent.

My problem: - I am using UIActivityViewController, but I dont know how to stop its process when I click on mail and insert some custom interaction between them.

Please, help.