Cost rate for Expenditure type

Hi,

I have defined Material, Machine, Labour, Overheads, Miscellaneous Cost etc. as Expenditure Types in Project Costing. I want to book expenditures against Projects, I know that I can do it by entering Pre Approved Expenditure batch. But how and where to define the Cost Rate/ate for these expenditure types? What is the correct method/ steps to do it?

Regards

Chaitanya