Hola,para contar las lineas podes usar algo asi,pone un boton en el formulario ,y indica la ruta en el codigo de tu archivo
Código:
Public Function Contar_Lineas(ByVal strTextFile As String) As Long
Dim F As Integer
Dim Lineas As Long
Dim str_Linea As String
F = FreeFile
Open strTextFile For Input As #F
Do
Line Input #F, str_Linea
Lineas = Lineas + 1
Loop While Not EOF(F)
Close #F
Contar_Lineas = Lineas
End Function
Private Sub Command1_Click()
Dim Path As String
Path = "C:\texto.txt"
If Path = vbNullString Then Exit Sub
MsgBox " Cantidad de lineas: " & Contar_Lineas(Path)
End Sub
saludos.