NIW filing

I am working as post doc in a university. One chinese colleague in my department told me that I can ask my boss to help me find some one to write recommendation letter for me. I asked my boss and he agreed to find some one in the funding company who know our work in the project. Now I have got all other letters, except this letter. My boss agree to check with the one in our funding company. Now I don't know if there will be any problem to get this letter. Does anyone has similar experience? and want to share?

Thanks a lot