Welcome, I am sorry that you are involved in this situation.
A child should never be raised in such a toxic enviorment, he is not only an alcoholic but has significant mental issues. Children carry their childhood into adulthood, your 4 year old daughter has already inherited the gene that predisposes her to addiction, and, living
with one only magnifies her predisposition.
In no way, shape or form should he be left in charge of babysitting your daughter, this would be an irresponsibile action on your part.
He is responsibile for solving his issues and you are responsibile to make your child your priorty.
Read all the stickies at the top of this forum and that of the Family & Friends of Substance Abusers, lots of helpful information at your fingertips. I would also recommend that you read Codependent No More and start attending Alanon meetings.