Have you tried to run a "execute SQL task" against the excel connection. I use this to create the excel sheets inside the file and mod the datatypes where neccesarry.
The syntax is verly similar to SQL:
DROP TABLE `Sheet_name`
go
CREATE TABLE `Sheet_name` (
`column1` VARCHAR(10),
`column2` VARCHAR(50)
)
The connection type is "Excel" The the connection property is the excel sheet?
Hope this helps