'Ctrl'+'V' is the universal key for 'Paste' used by many programs etc. It would be not a good idea to start manually altering the functions of 'Ctrl'+'V' . 'Paste' inserts the contents of whatever was 'copied' (universal copy keys 'Ctrl + 'C') eg: text into the current document or files and folders into other folders. It does not attach another document to a current document, keeping both separate as formatting may not be the same and both may need different programs to view. Attachments can then be detached or saved and opened using the appropriate software. Currently you can use these methods. In a Write message: click on 'Attach' select document and click on Open OR if you have set up 'keywords' to prompt you, an 'Add Attachment' button will pop up in bottom Status bar, which you can click on to allow you to select a document. OR As you are already seeing the document file, instead of right click and select Copy or Ctrl+C, why not simply use drag and drop. Left click and hold down to grab document you want to attach. Drag document and hover over the right side of the headers and an 'Attachment' section appears. Release the mouse to drop the attachment. Some default keywords are already set up, but can add additional ones. Keywords can be set up here: 'Menu icon' > 'Options' > 'Options' > 'Composition' > 'General' tab click on 'Keywords' button.