High C is brick wall

I am three months in as director of finance and operations of a 12 person NGO. Its accounting and management are in a shambles. I am a high D, my boss  (the Director of the organization) is a high S, a person with whom I have conflict,  Bob, is a high C.  Bob does not report to me, but I am the de-facto HR person, and more senior in level to Bob.
I have three problems  with Bob. He is leading us to fail our audit, he does not provide me with information or deliverables I request, and he is now calling in sick/working from home excessively. 
Bob is a loner, doesn’t fit into our office (we’re all Type As, he’s not), is anti-social, calls in sick excessively without appearing physically sick, and for the last two months has been working from home more than 50% of his workdays.
Regarding the audit,  I just sent out a note on new processes and procedures we must follow (to not fail our audit). I did not mention that we would fail the audit; I simply said “effective immediately, here are the new processes and procedures we must follow.” Bob refused to comply. I now have the task of explaining to him that we’ll fail the audit, if he continues to follow the processes he’s always followed. That I can handle.
Bob, in my calls for information or assistance, is nothing more than a brick wall. I have three instances where I have requested information, which he must compile and have received nothing but defensive replies, but never the information or deliverable I needed. Here’s his response when I asked him for a copy of a file (while we were forced to work from home due to weather): ” I have no electronic copy of the xx award letter. If you want to start scanning copies of grant award letters that I give you for your purposes, you're free to do so. I'll leave that to you.”   Because he works from home more than anyone else in the office, a) I would have expected him to have electronic access to his files, and b) I expected a yes or no answer. Instead, he usually answers as above, making his problem or job duty become my problem. Am I mistaken to assume that, as much as he works from home, he'd have electronic access to documents for which he is responsible for producing?
 I don’t see productivity arising from his work from home days. My fear is that other younger staff will begin “working from home” excessively, because Bob does it. He has become the talk of the office due to his “sick” and “work from home” days. . Bob has been counseled annually on his excessive sick days, which have sometimes exceeded his leave. His work from home is now the way he has found to get around that issue.  We have no formal policy on “working from home” and my high S boss, the Director of the Organization, rarely manages or sets policy for the organization. What do I do to nip this “work from home/not feeling well” problem?
Please help and counsel me on whether I bring up his previous lack of collaboration/work from home/sick days up when I explain the audit failure situation. I will need my Director to be on my side and be present in any meetings with Bob. How do I approach the situation?