change to glow texture on mouse click

im pretty new and i had an idea involving a hand in the corner where you could pick things up with magic like in amnesia. so that if i see an object about 2 meters away from me and i have it in the middle of my sight i can pick it up by clicking and holding my left mouse button also i would like whenever i hold my left mouse button the hand texture changes to a glowing one that looks like somesort of magic. and then when i release it it changes back to the normal texture and the objecft falls again.

can you give me some help please how to acomplish this??