Create Custom Tool to call AVRDUDE: Copy this stuff into the appropriate textbox in external tools.

In MC Studio, choose Tools | External Tools

Title:  Arduino Programmer AVRDUDE
Command: C:\WinAVR-20100110\bin\avrdude.exe
Arguments: <avrdude -c usbasp -p atmega8 -U flash:w:$(ProjectDir)Debug\$(TargetName).hex:i>

Be sure to check "Use Output Window"