Option Explicit
Private Declare Sub CopyMemory Lib "kernel32.dll" Alias "RtlMoveMemory" (ByRef Destination As Any, ByRef Source As Any, ByVal Length As Long)

Private Type MiUDT
    Nombre As String * 50
    Apellido As String * 50
    Edad As String * 3 'as byte < mmm no me funciona bien
End Type

Private Sub Form_Load()
    Dim MU1 As MiUDT
    Dim MU2 As MiUDT
    Dim sBuff As String
    
    sBuff = String(LenB(MU1), vbNullChar)
    
    With MU1
        .Nombre = "Leandro"
        .Apellido = "Ascierto"
        .Edad = 20 ':)
    End With
    
    CopyMemory ByVal sBuff, ByVal MU1, LenB(MU1)
    
    CopyMemory ByVal MU2, ByVal sBuff, LenB(MU2)
    
    With MU2
        Debug.Print .Nombre
        Debug.Print .Apellido
        Debug.Print .Edad
    End With
    
End Sub