Not possible with Adobe Reader.
Thanks for the answer
How is "Save As Text" called, when you go File, Save As Text? Which methods are called?
Select all, copy.
You mean you use Adobe Reader 9.3.1? It would be helpless if you want to use it to automate PDF to text. Adobe acrobat may help you automate PDF as text if you can afford it. Here is an alternative way to help you automate PDF to text--try to use PDF to text converter, which can help you automate many PDF files to text at a time. I think it is a more acceptable way compared with Adobe Acrbat. Have a try.