The Aircraft Container System SDK states on page 14 that the first entry is the one that defines the class ('type') of the contact point:
0= None
1= Wheel
2= Scrape
3= Skid
4= Float
5= Water Rudder
So if you open your .cfg, look for the contactpoints that start with a '1'.
If we take the two lines below taken from an aircraft .cfg file as an example, you can see that the first one is a wheel, and the second one is a scrape (a contact point used to define where parts of the aircraft touch the ground when making a wheels-up landing):
point.0 = 1, -19.120, 0, -3.6211945, 2165.354, 0, 0.551, 180.000, 0.327, 2.500, 0.39, 4, 4, 0, 164, 184
point.7 = 2, -22.020, 0, -1.90, 3000, 0, 0, 0, 0, 0, 0, 0, 0, 4
You can also derive from the info that Daiwiletti gave that the wheel probably is a tail wheel (Y=-19.120, X=0 and Z=-3.6211945) and the second one a tail scrape: Both are way back from the centerpoint (Y-value) but on the centerline (X-value) and relatively low (Z-value)