An openMSX TCL script to copy the contents of the current LISTing to your clipboard. Just dump this in your profile's openMSX/share/scripts directory and you can use the copy_ascii_listing_to_clipboard command

listing_manipulation.tcl

namespace eval listing_manipulation {
	proc strip_memory_addresses {str} {
		return [regsub -all -line {^[0-9a-f]x[0-9a-f]{4} > } $str ""]
	}
	proc copy_ascii_listing_to_clipboard {} {
		set_clipboard_text [strip_memory_addresses [listing]]
	}
	namespace export copy_ascii_listing_to_clipboard
}
namespace import listing_manipulation::*