shipping module for magento

I need a magento expert to build a shipping method for my magento. my requirement as below: i have 2 csv table: one is for zone table, and second one is rate table zone table has 2 column: postcode and ZoneID, this table is to divide all australia into 10 zones by postcode. for example: vic, 3000 rate table has 4 colum: zone_id, base charge, rate per kilogram, and weight-break, for example:vic, 8, 0.5, 10 if customer from vic zone bought product weight under 10kg (weight_break), the freight is $8 (base charge), if the weight is over 10kg, say 20kg, the freight is (20-10)X0.5+8=13 i neeed this shipping module only works when order weight over 20kg and handle fee adjustable at admin. the project need finished in 1-2 days once confirmation. and compatitable with lastest version of magento 1.3.2.3