> To summarize:
> 1. Read data from another program by ruby program
> 2. Data analysis by ruby program
> 3. action perform in the other program by ruby program

As far as I understand you want to interact with Win32 GUI application.
Try to use Windows messages to get data and perform actions on its GUI
controls (text area, buttons). 

All you need is:

1) Find the program window (== get it's handle) by title
2) Find the GUI control you want to work with (== get it's handle)
3) Send message to this control (for example - to get text from text box
you need something like WM_GETTEXT message (see MSDN for details), to
push a button WM_LBUTTONDOWN,...)

For step 1, 2 I cannot remember Win API functions by name, but you
shouldn't have any problems finding one (See MSDN, section about Window
functions).

It's very brief explanation. If you have more specific question - feel
free to ask.