Hello Jls, welcome to Step12.com
I'm doing my best to understand the question you have, but remember to cut me a little slack... if I get it wrong!
Reading your message, you mentioned that you're dad is in treatment, I'm adding one and one together, and it sounds like they're preparing or continuing a process that is often called "Intervention" (in treatment center speak) and "helping him hit bottom" (in AA speak).
I'm not sure how familiar you are with treatment centers and AA... we both have the same desire... to help alcoholics... and some treatment centers use AA's 12 Steps (because they work so well, expecially for when the person gets out of treatment). And, even though a lot of people who have gone through treatment centers... end up in AA... AA is different than treatment centers.
The reason for that long paragraph? My suggestion would be... that it would be best to ask your dad's treatment center counselor the questions, in regards to the impact letter. Myself, and I'm sure all the people who come and use Step12.com want to see your dad successfully stay sober... and none of us would want to do anything, or answer a question in a way, that might interfere with the Treatment Center's process, or his counselors process of helping your dad. And, depending on the way we might answer a question... if it regards treatment (which isn't AA), could interfere with the work the treatment center is trying to do.
Whatever you do... you feel right at home here and ask any questions you want to ask... and myself and hopefully some of the others will do our best to answer the questions... "according to our understanding and experience." We also have 12 Traditions, with our 12 Steps, and the Traditions remind us that in AA, "none of us are professionals" ... so our suggestions should never appear to be as coming from a "professional" ... even though we do have many professionals... that are simply members of AA.
I hope I didn't get carried away in giving you a long answer that didn't make any sense, when a shorter one would have been better... I'm not a professional.
We might even have some treatment center professionals who are members here at Step12.com ... but, one of the guidelines here, is that nothing we say should be considered as "professional answers." And, different treatment centers have different methods that they use... that's why I suggest talking to someone at the treatment center that your dad is in... to answer those kinds of questions for you.
I hope that helped! Once again, welcome to the website. Glad you are here. And, keep coming back!