Private Sub Form_Load()
    MsgBox (char2bin("a"))
    MsgBox (txt2bin("Hello World"))
End Sub
 
Function txt2bin(str2bin As String) As String
    Dim result As String
    For i = 1 To Len(str2bin)
        result = result & char2bin(Mid(str2bin, i, 1))
    Next i
    txt2bin = result
End Function
 
Function char2bin(chr2bin As String) As String
    Dim result As String
    Dim char2asc As Integer, total As Integer
    char2asc = Asc(chr2bin)
    For i = 7 To 0 Step -1
        If char2asc >= (total + (2 ^ i)) Then
            total = total + (2 ^ i)
            result = result & "1"
        Else
            result = result & "0"
        End If
    Next i
    char2bin = result
End Function