Whatever we write, it isn't going to be as grand as whatever you come up with :)
but if i had to give it a shot:
"God/dess of ___________, please bless this pen with your wisdom and guidance, may my hair bestow myself into this pen, and my this pen serve me as my magical tool, through out my life's journey. So be it."
Feel free to re-word it as much as you want. Make it your own xP