MDX to pick the data from first day of the current month

Hi

I need to make a mdx query to pick the data from first day of the current month.

SELECT [Measures].[Internet Sales Amount] ON COLUMNS,

[Date].[Fiscal].[Date].MEMBERS ON ROWS

FROM [Adventure Works]

The above query returns around 4 years of data, but I need the data from first day of the current month.

Could anybody help me out!!!

Thanks

Randy