Something like this:
Dim sql As New StringBuilder("SELECT * FROM table WHERE column IN (")
Dim parts As String() = txt_Param.Text.Split(","c)
For i As Integer = 0 To parts.Length - 1
cmd.Parameters.Add("", Odbc.OdbcType.Char).Value = parts(i)
If i <> 0 Then sql.Append(", ")
sql.Append("?"c)
Next
sql.Append(")"c)
cmd.CommandText = sql.ToString()
You might want to look at
Dapper[
^], which makes this sort of query much easier.