Going to leave this here for future reference, hoping that it may help somebody in the future.
When copying the code @Driver posted here and converting my normal and specular maps to .dds format, this happened:
The edges on the wig still looked white, and when lowering the brightness on the wig, it lost all definition. When saturating it, the white edges remained, gaining a separate coloration from the intended one.
So, I reverted to just adding the normal path (PNG version) without the specular, and this is the result without, and with saturation:
The code on the pass file for my version reads:
[pass]
name = CustomModel
stage2 = F_Wigs39_N.png
stage3 = hair_s2.png
I'm sure the version uploaded by @demonv1 solves the issues I had since he did some more work on Photoshop, so as of now, that will be the version I will put up. Expect the model for this test, Aya Ramos, to be uploaded later today!
Many thanks to @Sexvision, @aardy, @Driver and @demonv1 for their assistance with this! Now I can try retextures on many other hairs that I'm interested in!