Program a GUI in C/C++ for arduino and mouse cursor control

The control will be through Serial comm-- between Arduino and PC through rs232 port by following methods:

a. From mouse courser motion like that in Games or
b. From keyboard arrow keys

Neither is appropriate. The Arduino understands bytes, like letters. Send 'f' to move along the x axis in the positive direction. Send 'b' to move along the x axis in the negative direction. Send 'u' to move along the y axis in the positive direction. Send 'd' to move along the y axis in the negative direction.

Secondly i want to create GUI for different action to perform:
e.g

  1. Reloading (GUI should have Reload button)
  2. magazine changing (GUI should have magazine change button) etc..

Go right ahead.

How, exactly, is the GUI supposed to reload the weapon? How, exactly, is the GUI supposed to change the magazine? How, exactly, does changing the magazine differ from reloading?

please give me the solution in each case

Why? Neither is appropriate.

and also want to know which programming software can i use to create GUI that can communicate with Arduino.

Any one that you are familiar with that can write to the serial port.