From AFI 36-2501 Officer Promotions and Selective Continuation:
2.10. Writing Letters to a Board.
2.10.1. Officers eligible for promotion may write a letter to the board. Eligible officers:
2.10.1.1. Submit the letter in good faith, and ensure it contains accurate information to the best of their knowledge.
2.10.1.2. Sign and date the letter.
2.10.1.3. Send the letter to HQ AFPC/DPPPO so it arrives no later than (NLT) 2359 (Central
Standard Time) the day prior to the board convening date. Letters arriving after 2359 the day prior to the board will not be presented to the board for consideration.
2.10.1.4. If the letter writer requests return of the letter, he/she must provide a stamped,
self-addressed envelope.
2.10.2. HQ AFPC/DPPPO advises officers when letters do not meet the above requirements and either returns or destroys the letter.
2.10.2.1. Letters on behalf of other officers are not permitted, although individuals may provide
relevant attachments to their own letters. Any attachments addressed directly to the board will
cause the entire letter to be returned to the eligible officer.
2.10.2.2. Attachments or documents that can become a permanent part of the officer's record; e.g., draft/proposed/final PRFs considered by previous selection boards, unsigned draft/proposed officer performance reports or decoration narratives are not permitted.
2.10.2.3. Letters with attachments will not exceed 10 pages: 5 two-sided pages or 10 one-sided
pages. Letters exceeding 10 pages will be returned to the officers.
Try and get a "tentative hire letter" from the Guard unit that is interested in picking you up. If you can get that, write a letter to the board explaining the cirumstances you face if they pass you over before the Guard is able to gain you officially. Then, and probably most difficult, find a way to get it to AFPC/DPPPO by 2359 tonight. Worst case I would try and fax a copy to any office in AFPC that I could get a number for and follow up with the original as fast as possible. Maybe RND command post would do you a favor and run the fax over to AFPC and slide it under DPPPO's door?