I'll assume we're talking about web pages from the mention of <input> and Submit buttons. To be honest, more context and more thought should have gone into the original question to clarify what you're trying to learn. How to ask questions the smart way.

The server receiving data from the client has no access to the client's clipboard, so unless your client is built in Perl, ignore the suggested Win32::Clipboard advice. A JavaScript feature might be able to pull clipboard data and put it into a hidden post field but this isn't JavaScriptMonks.

This has nothing to do with Perl at all. Why was this up-voted as many as nine times? Why was this approved as a question for PerlMonks at all? Maybe I'm just a curmudgeon but I would like to learn and sometimes help with Perl issues here.