Need help on MDX query to change the dimension value on specific case( for displaying as result)

hi, I need help for the following MDX query.

SELECT NON EMPTY
(
	FILTER([Date].[Fiscal Year].[Fiscal Year], ([Date].[Fiscal Year].CurrentMember.MemberValue=cDate('3/1/2012')))
	,[Ledger Rowdefinition].[Name].[Name]
)  ON ROWS,
({{
	[Measures].[Actual Amount],
	[Measures].[Budget Amount]
}}) ON COLUMNS
FROM [Ledger Row Definition Actual Vs Budget]

And It result's Like the following:

Fiscal Year        Ledger Rowdefinition            Actual Amount          Budget Amount

--------------      -------------------------------       -------------------          ------------------

2012             ABC                                          456464666               987979797

2012             XYZ                                         4654646                       46464646

Now, I Want to Display the result as,

                                      If ' Ledger Rowdefinition' =XYZ then make it 'PQR'

so, The result should be as below:

Fiscal Year        Ledger Rowdefinition            Actual Amount          Budget Amount

--------------      -------------------------------       -------------------          ------------------

2012             ABC                                          456464666               987979797

2012             PQR                                         4654646                       46464646

How can I do this task in MDX. Looking for some kind response.

Regards,