Faizan,
Here is the sequence of events as I understand it:
1. You create an asset and during creation you enter a cost center in the time-dependent tab.
You need a rule that will derive a fund center, functional area, etc. based on the cost center.
2. You enter the asset number of the asset created in 1 above in an acquisition posting.
You need the Function Module rule that reads the account assignments from the asset master data.
If the first rule does not work then the second rule has nothing to read.
Thanks
Shyam