Here are my first thoughts on this...
Excellent spell idea, but..
I personally would design it as a PeCo spell with a (Re) requirement rather than the other way around.
Since you are first removing the hair and only thereafter needing to draw it to you, the control aspect is to my mind, secondary.
Removing a lock of hair would be, as written, "doing superficial damage to Target" (as per example given) pg. 133. This is base level 3.
Now, one could do it with Voice range for a casting level of 10, however, consider that Voice range to Target must incorporate a volume necessary to reach the target, suggesting that the Target will undoubtedly hear you casting the spell. Considering also that what you are attempting to do is to obtain an AC to them for far worse spells, this doesn't strike me as a particularly covert means of acquiring the same. Range Sight would allow for far more stealth (from a rooftop say).
That would make the PeCo aspect level 15, as the guidelines are written, however, there is an argument (dependent on the flexibility of any given SG mind you) that unlike the example given in the PeCo guidelines, you aren't removing ALL the Target's hair, but merely a small lock. So I might be inclined to call the base effect level 2 and allow the PeCo spell to clock in at a casting level of 10.
The secondary aspect of the spell presents its own issues for any given SG to decide upon. Does one take it as an integral and indispensable effect of the spell or an added effect? If integral then it imposes no further magnitudes to the overall spell and you get a level 10 spell with requisite as per your original design. If not (and I DO tend to side with this view) then it IS an added kudo to the spell and you should make it level 15, since you ARE getting a valuable asset to your nastier attack spells if you succeed.
Considering that this spell could be just as easily invested into an item with considerably cheap penetration bonuses added onto it, this is the lowest level I should think most SGs would be inclined to allow.