Typed Data between Excel and VB.Net

Question

Creating an application to run canned queries. The queries use input data provided by end users, in the form of Excel worksheets. Knowing the needed input column data types beforehand, I've created typed datatable objects. How can I verify the provided data is typed correctly when importing from Excel?

My query seems to convert numeric data to strings to fit my typed datatable. I do not want this, I want to throw an error in this case. Also for input columns containing multiple types of data, the query converts the minority type to null values. This would be okay with the constraint to disallow nulls on the typed tables, except the query often returns several extra rows of null values even in correctly typed input datatables.

Code below...how can one verify provided excel data strictly follows a schema?

Dim strInputData As String = "Desktop\testfile.xlsx"
Dim strCon As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & strInputData & ";Extended Properties=""Excel 12.0 Xml;HDR=YES"";"
Dim connection As New OleDb.OleDbConnection(strCon)
Dim command As New OleDb.OleDbCommand
command.Connection = connection
Dim inputDataSQL As String = "Select [Member ID], [Carrier ID] from [Sheet1$]"
command.CommandText = inputDataSQL
command.CommandTimeout = 0
Dim inputData As New typedDataTable
connection.Open()
Try
    inputData.Load(command.ExecuteReader(CommandBehavior.CloseConnection))
Catch ex1 As System.Data.ConstraintException
    connection.Close()
    MsgBox("Invalid data. Please use template or contact developer.")
    GoTo [Exit]
End Try