If it's acessible from the Plus menu, it'll be using the event:
code:
OnEvent_MenuClicked()
Within that event you'll create the interface window (MsgPlus.CreateWnd). Then use:
code:
PlusWnd.SetControlText()
The function to read from a text file can be found on these forums, on Google and I'm fairly sure in MSDN (as well as function to save)
Then use:
code:
OnWindowIdEvent_CtrlClicked()
and
code:
PlusWnd.GetControlText
to save the contents of the text box back to the text file...
Thats the basics. If you need any more help with the functions mentioned here, they are covered in the scripting documentation and possibly on the forum again. If you can not find the functions to Read/Write to a text file (should be really easy btw), I'll post more detail