Do you expect the forum to provide you with a welding procedure for a super alloy?

That's not going to happen.

Tell us a bit more about your project and provide some specific questions and you will get some sound data and assistance.

By the way... There are a variety of Hastelloy C's

Hastelloy C22
http://www.haynesintl.com/pdf/h2019.pdf

Hastelloy C4
http://www.haynesintl.com/pdf/h2007.pdf

Hastelloy C276
http://www.megamex.com/hastelloy-c-276-c276-nickel-alloy.htm