Maybe I have missed your objective, but I am not sure why you need any PDF processing, OLE or use the clipboard.
It is a bit unclear what you want the Adobe Acrobat "Select All" process to select e.g. the entire file content in PDF format, text only, etc.
But my interpretation of what you want to do is read a binary file (which is in PDF format) then place in a datawindow, presumably so you can then save it to a database. You do not want the PDF content to be visible at any point. And the end-user probably does not want their clipboard content clobbered.
If I have got this right, you only need to read the file into a blob variable (FileReadEx() function), then save the blob to the database with an SQL statement (UPDATEBLOB),
Stuart