Imports System

Public Module Module1

    Public Sub Main()

        Dim directory as System.IO.DirectoryInfo = new System.IO.DirectoryInfo("c:\\source")

        ' verify the directory actually exists

        If Not directory.Exists then

            throw new Exception(String.Format("Source directory ({0}) does not exist.", directory.FullName))

        End If

        ' retrieve only the files we want to process

        ' files are named like invoices_20191217.txt

        ' directory contains other files, like invoices_20191217.xml

        For Each file As System.IO.FileInfo In directory.GetFiles("invoices_*.txt")

            file.MoveTo(String.Format("c:\\process\\{0}", file.Name))

        Next

    End Sub

End Module