How To Load Several Excel Files In The Same Database (same Structure, But Column Format Different)

Hello,

Here's my need :
In one directory there's several excels file. Theses file have the same structure :
col : LOOKID, LOOKNAME, ASMPID, ASMPNAME, LOOKTYPE, LTYP_NAME, PAR_TYPE, PTYP_NAME, PARAMETER, VALUE.
The problem is that the cell format of the PARAMETER col. is different bewteen excel files. It could be date, numeric, ... The col destination in sqlservr database is Varchar(10).

I've created the ssis package with a ForEach Loop, and in the ForEach loop I've created a Data Flow Task.
In the data Flow Task I've created an excell source file (using excel file with col PARAMETER in date format) with an OLE DB destination.

When I launch the package on the same excel file as the one using to create Excel Source object it's OK, no errors, and data in the sql table are OK.
But when I launch the package on Excel file with col. PARAMETER in numeric format, there's no execution errors, but in the destination table the value of the PARAMETER col. is transform in date format.

I tried to change in Excel source object the datatype of the input PARAMETER col, but I've got some compilations errors. It seems that SSIS recognize automaticaly excel source data type col. But may be I did something wrong in the excel source settings ?
Is there a way to force the excel source datatype with varchar(10) ?

I've also tried to do the treatment with an script task but my vb.net knowledge isn't enought to do that.

If you have some suggestions, I'm listening.

Thanks

Luffy