Use AppleScript with the Guest OS
You can use AppleScript to open various files and websites in the guest OS applications. You may need this when creating automated workflows.
To make the explanation more vivid, let's assume that you need to open some .txt file in Windows Notepad using AppleScript (in AppleScript Editor). The syntax of this command is as follows:
tell application "Notepad"
open "/Users/username/somefile.txt"
end tell
As an example of opening a website in the guest OS application, let's assume that you need to open "www.parallels.com" in Internet Explorer. The syntax of this command is as follows:
tell application "Internet Explorer"
open "//www.parallels.com"
end tell