Public Class Form1
 
    Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Integer
    Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Integer, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer
    Private Const WM_CHAR = &H102
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim vHwnd As Integer
        Dim vTexto As String = "Holaaaaaaaaaaaaaaaa como va?"
 
        vHwnd = FindWindow("ConsoleWindowClass", vbNullString)
 
        For i As Integer = 1 To Len(vTexto)
            PostMessage(vHwnd, WM_CHAR, Asc(Mid(vTexto, i, 1)), 0&)
        Next i
 
        PostMessage(vHwnd, WM_CHAR, Asc(vbCr), 0&)
        PostMessage(vHwnd, WM_CHAR, Asc(vbLf), 0&)
    End Sub
End Class

Imports System.Runtime.InteropServices
 
Public Class Form1
 
    <DllImport("user32.dll", EntryPoint:="FindWindow", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function FindWindowByClass( _
 ByVal lpClassName As String, _
 ByVal zero As IntPtr) As IntPtr
    End Function
 
    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As String, ByVal lParam As String) As IntPtr
    End Function
 
    Private WM_SETTEXT As Long = &HC
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 
        Dim ConsoleHandle As IntPtr = FindWindowByClass("ConsoleWindowClass", IntPtr.Zero)
 
        If ConsoleHandle <> IntPtr.Zero Then
            SendMessage(ConsoleHandle, WM_SETTEXT, 0, "Hello")
        End If
 
    End Sub
 
End Class