Thanks for answering me! I will follow in your footsteps and tell you the result!
NevesOma, I have a doubt now. I did as you said, I followed your steps, I created the new ukx, I already put it inside the l2 folder, but now, I need to create a file with the texture that fits .utx, or inside the created ukx file the texture is included? if it is included how should i describe it within weapon.grp
PS: the filename is vega.ukx