Need some insight on making a graph using .txt file

I'm working on a project that uses an embedded board with 2 accelerometers. These accelerometer generate some data

that is being dumped in a compact flash (CF) on the embedded board, that is being accomplished by using low level C.

The CF is then hooked up to a windows PC, that runs a GUI (the GUI is being built using Qt Creator) and the file is

accessed through it. So my question is if the data file that is being generated in CF is a .txt file, how can I generate the

graph of that data as soon as it is chosen from File->Open-> test.txt?

I am new on programming GUI's but I have a rough idea on programming using C++ and some other object oriented

language.

Any help or ideas would be appreciate it. Thanks in advance.