Adding the rest of the properties

Public Property Get Enabled() As Boolean
    Enabled = Command1.Enabled
End Property

Public Property Let Enabled(ByVal New_Enabled As Boolean)
    Command1.Enabled() = New_Enabled
    PropertyChanged "Enabled"
End Property

Public Property Get Font() As Font
    Set Font = Command1.Font
End Property

Public Property Set Font(ByVal New_Font As Font)
    Set Command1.Font = New_Font
    PropertyChanged "Font"
End Property

Public Property Get Picture() As Picture
     Set Picture = Command1.Picture
End Property

Public Property Set Picture(ByVal New_Picture As Picture)
Set Command1.Picture = New_Picture
    PropertyChanged "Picture"
End Property

Public Property Get DisabledPicture() As Picture
     Set DisabledPicture = Command1.DisabledPicture
End Property

Public Property Set DisabledPicture(ByVal New_DisabledPicture As Picture)
    Set Command1.DisabledPicture = New_DisabledPicture
    PropertyChanged "DisabledPicture"
End Property

Public Property Get MousePointer() As MousePointerConstants
    MousePointer = Command1.MousePointer
End Property

Public Property Let MousePointer(ByVal New_MousePointer As MousePointerConstants)
    Command1.MousePointer() = New_MousePointer
    PropertyChanged "MousePointer"
End Property

Public Property Get MouseIcon() As Picture
    Set MouseIcon = Command1.MouseIcon
End Property

Public Property Set MouseIcon(ByVal New_MouseIcon As Picture)
    Set Command1.MouseIcon() = New_MouseIcon
    PropertyChanged "MouseIcon"
End Property

Public Property Get Caption() As String
    Caption = Command1.Caption
End Property

Public Property Let Caption(ByVal New_Caption As String)
    Command1.Caption() = New_Caption
    PropertyChanged "Caption"
End Property

Private Sub UserControl_ReadProperties(PropBag As PropertyBag)
    Command1.BackColor = PropBag.ReadProperty("BackColor", &H8000000F)
    Command1.Enabled = PropBag.ReadProperty("Enabled", True)
    Set Font = PropBag.ReadProperty("Font", Ambient.Font)
    Set Picture = PropBag.ReadProperty("Picture", "")
    Set DisabledPicture = PropBag.ReadProperty("DisabledPicture", "")
    Command1.MousePointer = PropBag.ReadProperty("MousePointer", 0)
    Set MouseIcon = PropBag.ReadProperty("MouseIcon", "")
    Command1.Caption = PropBag.ReadProperty("Caption", "Button")
End Sub

Private Sub UserControl_WriteProperties(PropBag As PropertyBag)
    Call PropBag.WriteProperty("BackColor", Command1.BackColor, &H8000000F)
    Call PropBag.WriteProperty("Enabled", Command1.Enabled, True)
    Call PropBag.WriteProperty("Font", Font, Ambient.Font)
    Call PropBag.WriteProperty("Picture", Picture, "")
    Call PropBag.WriteProperty("DisabledPicture", DisabledPicture, "")
    Call PropBag.WriteProperty("MousePointer", Command1.MousePointer, 0)
    Call PropBag.WriteProperty("MouseIcon", Command1.MouseIcon, "")
    Call PropBag.WriteProperty("Caption", Command1.Caption, "Button")
End Sub