How to assign actual cost rate in the update ?

Hi,

This is my first post here in Planning Planet .. it's a question and i hope get ur help ..

.......................................................................................................................

If i want to made an update for my project .. how I can assign actual cost rate for the materials ..

here, my question, not actual material cost, but actual rate..

for example, suppose I have a concrete material resource which have a cost of 150 $/M3

and when I doing the update I would like to change to the actual cost of 200 $/M3 .. then how to doing this ??

..........................................................................................................................

hope to receive your answer quickly ..