Balance to COS (COGS) would be Inventory.
My question is do you just want to fix it going forward or are you trying to recalculate the past?
Kim and Yun give helpful information on getting value into your inventory. The adjustments would post to inventory and inventory adjustment.
If you want to build history from a manufacturing system, that's going to be VERY complex. How many transactions have already been posted? If you have an active system it may just require backing into the numbers and posting G/L entries. Then zeroing the inventory accounts and doing the revaluations Yun and Kim mention.
Doing it "right" at a minimum would mean revaluing all purchase transactions on the date of their posting, then allowing the Adjust Cost to forward that through the system.