Fixed Assets Depreciation Calculation

Hi,

I need to calculate depreciation in the following manner:-

The life of assets is 5 yrs i.e. 60 month, method of depreciation is straight line.
Always keep 10% as residual value for the assets.
consider the following example:-
Cost of Acquisition :- 4149.00
Life of Assets :- 60 month
Method of Depn. :- Straight Line
Residual Value :- 10% of cost
Monthly Depn :- (4149 * 0.90)/60 = 62.24

So how we map this in AX 2009

rgds
dhananjay