Пользуюсь такой функцией, которая копирует один объект Ent в блок ToBlock. При необходимости можно указать вектор смещения NewBase.
Возвращается ссылка на новый объект.
'''
Public Function CopyToBlock(Ent As AcadEntity, _
ToBlock As AcadBlock, Optional ByVal ErrResult As String, Optional NewBase = Null) As AcadEntity
Dim t0(2) As Double, t1(2) As Double
Dim pAO(0) As AcadEntity
Dim pRet, pIdP
Dim pACD As AcadDocument
Set pACD = Ent.Document
Set pAO(0) = Ent
pRet = pACD.CopyObjects(pAO, ToBlock, pIdP)
If Not IsNull(NewBase) Then
On Error Resume Next
t0(0) = NewBase(0)
t0(1) = NewBase(1)
t0(2) = NewBase(2)
pRet(0).Move t0, t1
If Err Then Err.Clear
End If
Set CopyToBlock = pRet(0)
End Function