Itterative alignement confusion

[Mranaskw]

Hello,

I'm currently still learning about programming and have covered all the basics , but yesterday i came across a part (a curved "bent" headlamp lens) and felt confused on how to align that thing ,
the part looks something like this

http://www.oemxenonshop.com/OEM-Xeno...eplacement.JPG

can u suggest your alignment ideas

because i used to pick features on a plane surface or edges , is it okay to pick plane on an axe that is not plane ?

MORE IMPORTANTLY : i have reviewed the program of this part because it was already created by another team , the hits were taken separately (for ex the plane was taken as two hits below the part and one hit above , the line was taken as one hit from the left side and second hit is from the other side of the part , this is crazy i don't get how can an alignment hits be taken separately please explain it to me because i wont feel relieved till i for-fill my curiosity)

Please if you have the answer of my question ,kindly do not leave without a reply , thank you so much

[JEFMAN]

Maybe you could find the answer on the print ?
Something like A1, A2 and A3 which are used to create the plane.
On this kind of part, very often, the origin is the origin of the vehicle, not this of the part, so you can have some meters of difference between the cmm coordinates and the part one.
It's the print (or the cad) that defines the alignment, so it's hard to help you without seeing it.