copy paste text

[DL]

Hi,
I have an app. that opens pdf documents.
Now i would like to use the text selectiontool of the pdf interface to
select text and then when a user presses a button it should automatically
copy the selected text in the pdf file and add it to a textbox in my app.
(p.s. the pdf viewer is integrated/implemented in my app. and they're both
on the same form : textbox & pdf field)

I thought of the following:
When a button is pressed, the app. focuses on the pdf field
and then somehow forces a ctrl-c (copy)
then focuses on the textbox and then forces a ctrl-v (paste)

I get their till the ctrl-c stuff...
Does anybody have an idea how to do this?
I know I read it somewhere a long while ago but I havn't got a clue where
that was,...
thanx