I did a search and it seems that you have to press and hold analog left/right and then rotate the camera left/right (you have to rotate the camera the same direction you are walking).
If I remember correctly you can't rotate the camera in GOW, so I don't know If it will work.
The only recomendation that I have is buying a 360 controller (it's pretty cheap anyway) and using it to pass this part in specific. In the end you will have a good controller that works flawlessy on windows.
EDIT:
It seems that there's a PPSSPP function called "On-screen touch controls".
If you enable it a transparent overlay of the psp buttons will appear on the screen (like the android version)
It works with the mouse so you have to click the analog and do the circle as you are doing with your thumb on a real psp.
Hope it helps.
If I remember correctly you can't rotate the camera in GOW, so I don't know If it will work.
The only recomendation that I have is buying a 360 controller (it's pretty cheap anyway) and using it to pass this part in specific. In the end you will have a good controller that works flawlessy on windows.
EDIT:
It seems that there's a PPSSPP function called "On-screen touch controls".
If you enable it a transparent overlay of the psp buttons will appear on the screen (like the android version)
It works with the mouse so you have to click the analog and do the circle as you are doing with your thumb on a real psp.
Hope it helps.