Object Stream1 String filename, text Number fileID, streamsize If (!OpenDialog(NULL, "Replace one by another", GetApplicationDirectory(2,0) + "xyz.txt", filename)) Exit(0) fileID = OpenFileForReadingAndWriting(filename) Stream1 = NewStreamFromFileReference(fileID, 1) streamsize = Stream1.StreamGetSize() While( Stream1.StreamGetPos() < streamsize ) { text = Stream1.StreamReadAsText(0, 1) /* The IF commands below uses single capital-case letter to replace single low-case letter in the '.txt' file. This replacement can also be done with single symbols such as '.', ','. */ If (text == "H") { Stream1.StreamSetPos(1, -1) Stream1.StreamWriteAsText(0, "h") } } CloseFile(fileID)