Setting DataTable column type does not persist to MS Excel

I am using the MS Jet driver 4.0 to export a .dbf file and its associated .dbt file. The problem I am having is that even after several hours of searching, the data in my columns are all "memo fields," meaning they are all strings/text. Since this is the case, I cannot add up any numeric values, as they are seen as text and will print a SUM of 0. I have tried multiple ways of setting the column type as follows, but none of them appear to have any effect on the output...they are still text values.

DataTable.Columns.Add(COL_HRS, typeof(System.Double)); 

Is this a problem with the MS 4.0 Jet Driver? Has anyone else ran into this? Thanks in advance.

I don't have a complete sample.  I dug this out of a 10 year old VB 6.0 app that worked heavily with dbf files.  I use to use classic ADO with the Microsoft dbase driver.  Here is the connection string:

"DBQ=" & sDBPath & ";Driver={Microsoft dBase Driver (*.dbf)};DriverId=277;FIL=dBase4.0"

This "might" work with the .NET Odbc classes and "might" work better than the Jet provider.

Robbe,

It seems reasonable that using the dBase driver has the potential to solve the problem. Currently, I'm working on using the Visual FoxPro driver to solve it also. Unfortunately, I feel like these could be work-arounds to the real problem, unless there's something I'm just missing.