Private Type cD
    A As Long
    B As Long
    C As Long
    D As Long
End Type
 
Private Type tStrg
    tStrg As String * 8
End Type
 
Private Sub Form_Load()
    Dim One As cD, Two As cD, Res As cD
    Dim LS As tStrg
    LS.tStrg = "86420"
    LSet One = LS
    LS.tStrg = "6020"
    LSet Two = LS
    ' Aquí no se como restar ONE - TWO usando el UTD Res
    ' El resultado se mostraría así ..:
    With Res
            ' Operaciones que no se como .¿?
    End With
    LSet LS = Res
End Sub

 
Option Explicit
 
Private Type udtDouble
    value As Double
End Type
 
Private Type udtStr
    value As String * 8
End Type
 
Private Sub Form_Load()
Dim One     As udtDouble, _
    Two     As udtDouble, _
    Res     As udtDouble
Dim tStr    As udtStr
 
 
    tStr.value = "8"    '1000 0000
    LSet One = tStr
 
    tStr.value = "2"    '0010 0000
    LSet Two = tStr
 
    Res.value = (One.value - Two.value) ' 1000 0000 - 0010 0000 = 11000000 = (192 >> 4) = 12
    LSet tStr = Res
 
    Debug.Print tStr.value '= 192
    Debug.Print Asc(tStr.value) '= 12
    
End Sub