Si te refieres a abrir y guardar un archivo de texto en un TextBox fijate con esto:
Text1.Text=FileToString("MiArchivo.txt")
Public Function FileToString(FileName As String) As String
Dim hlngFile As Long, strFile As String
hlngFile = FreeFile
Open FileName For Binary Access Read As hlngFile
FileToString = vbNullString
strFile = String(FileLen(FileName), " ")
Get hlngFile, , strFile
Close hlngFile
FileToString = strFile
End Function
Y para el proceso inverso:
StringToFile Text1.Text,"MiArchivo.txt"
Public Function StringToFile(StringText As String, FileName As String) As Long
Dim hlngFile As Long
hlngFile = FreeFile
Open FileName For Binary Access Write As hlngFile
Put hlngFile, , StringText
Close hlngFile
StringToFile = FileLen(FileName)
End Function
