Hi jenniferw,
Take a look at GL!Bal3.sam in the sample data. It uses "gldata.BAL_PY" for the balance sheet balances you are looking for. (For that matter, take a couple of minutes and review all the statements included with Adagio in the sample data - they demonstrate many "cool" features).
For P&L accounts, use "gldata.LYY" to pick up the prior year YTD net changes for the accounts.
PS - Could you update your profile please to include a company name? many thanks.
I'm sure we could show you a lot of cool things your can do with the Financial Reporter if you took a webinar. Check them out.
For example, did you know that you can drill down from a cell on the financial statement by using the right mouse button and selecting "Details"? You can double click your way down to the posted transactions in any account-department-fiscal period.