Hi,
as has already been noted it's not possible to tell exactly what you're after however I've done stuff like this in MS Office apps before - it's not always straightforward to automate a Select-Copy-SwitchApp-Paste operation even within standard Office apps...

Assuming one of the apps is a MS Office app you should hit ALT+F11 and create a new module in the VBA IDE then figure out what you want to do with Application.SendKeys (using the Windows help to get the special characters for ALT/Ctrl etc) then, once you know what you want to do (doesn't really have to be quite working) try converting it to Perl (if that's the best solution)...

'This is VBA in Excel
Dim thisBook as Workbook

'need to add ref in Tools/References
Dim otherApp as Word.Application 
Set otherApp = GetObject("Work.Application")
otherApp.Activate

'Send the keystrokes...
Application.SendKeys "keystrokes"
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and in Perl

use strict;
use Win32::OLE;
my $WordApp = Win32::OLE->GetActiveObject("Word.Application");
#blah blah
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HTH - Mark