When you say the administratgor will not let the "community" have sight of the bank statement, do you mean anyone in the community? Surely the president at least can see it - after all, he/she must be a signatory on the account.
The simple answser to the question "where would you start....." is obviously, the bank! The president and any other committee members who are signatories can simply go to the bank and ask for statements.
In our community, any owner who wishes, can have online access to view the bank statements (not to make any transactions of course). In the interest of openess and honesty, I believe this is a good idea; you could propose it at the next agm.