when downloading to excel sheet leading zeros are truncated

Hi,

I am downloading the Internal table datas into Excel sheet using

    CALL METHOD cl_gui_frontend_services=>gui_download.

The laeding zeros of fields are truncated, how to bring these zeros in excel sheet.

My requirement is exactly the datas of internal tables should be copied to Excel sheet without any truncations of leading zeros,Is there any FM which can convert exactly to excel sheet.

With Thanks,

Dina