Xcelsius+Live office

I am getting a Cross tab from Webi to Xcelsius using Live office and Embed into a spread sheet..

Intially there were 4 rows in the spreadsheet which change dynamically according to the parameter which I pass..

When my parameter value changes I got 2 new rows and additional 2 rows from existing spreadsheet..I mean its Overwriting the spreadsheet with out removing the Previous valus..

Please Provide workaround for this..