You can use the CopyFromRecordset function to populate the spreadsheet:
Iy you have a recordset called rstExcel containing the data to be copied, and have ensured this matches the columns needed to populate in the spreadsheet - in this example, row 1 in the spreadsheet already contains the column headers, so I copy the data starting at Row 2, Column 1
ActiveSheet.Cells(2, 1).CopyFromRecordset rstExcel
More details can be found here:
http://msdn.microsoft.com/en-us/library/aa165427(office.10).aspx