How to set up a new depreciation method needed for Hong Kong Tax book in Oracle FA R12?

What would be the best way to set up a new depreciation method in Oracle FA R12 that requires the following:

• No salvage value
• No useful life
• Assets are depreciated until they are retired
• First year depreciation - 60% additional allowance plus 20% of NBV (after 60% applied) in the purchase year no matter which month the asset was purchased
• Second and remaining years depreciation - 20% of NBV
• Year of retirement - 20% of NBV and write-off of residual value can't be recognized as loss for deduction for calculating Hong Kong profits from a tax perspective unless we can provide certain documents as proof for the retirement of the asset and Hong Kong tax authority approves our application