Thanks so much for so many excellent replies. I appreicate all of them I finally 'have to' give up this 'bad' design because I can get it working but it's very messy and probably not worthwhile spending too much time on it. Just a quick note; I get writer part working like this, which is enssentially the same as suggested.
string path = @"C:\Documents and Settings\";
string filename = "testernew1.txt";
var fi = File.Open(path + filename, FileMode.OpenOrCreate, FileAccess.Write, FileShare.ReadWrite);
var sw = new StreamWriter(fi);
for (int j = 10; j < 0; j--)
sw.Write(j);
sw.Flush();
fi.Flush();
sw.Close();
fi.Close();
Apparently, the reader part is very simliar. I am not familiar with message queque so I am going to look into it; also someone told me that it also be done by using remote charting which I assume is more complicated than message quque? Anyway, it would be great if someone can show some examples of either using message queue or remote charting. Thanks again for all the replies!