Do they look like [http://www.asusparts.eu/en/Asus-13050-74903000|this]? ([http://www.asusparts.eu/en/partfinder/Asus/Notebook/U%20Series/UX32VD%20(UX32V)#Screw|Source])
It lists it as "'''M2*2.5L+0.5(3,0.3)(K)T5'''" on the parts site. I noticed it said T5, and the twelve screws are T-5 torx screws.
To be quite honest, I can't really determine what the thread size is based on that string of mumbo-jumbo, but it does look like measurements. The teardown [guide|10120|does mention] that these screws are '''not proprietary''', so they should be readily available somewhere.
For what it's worth, I hope this at least helps point you in the right direction!