Option Explicit
'Graham Mayor - https://www.gmayor.com - Last updated - 01 Sep 2021 
Sub InsertMyBuildingBlock()
Dim oTemplate As Template
Dim oAddin As AddIn
Dim bFound As Boolean
Dim i As Long
    'Define the required building block entry
Const strBuildingBlockName As String = "Building Block Name"

    'Set the found flag default to False
    bFound = False
    'Ignore the attached template for now if the
    'document is based on the normal template
    If ActiveDocument.AttachedTemplate <> NormalTemplate Then
        Set oTemplate = ActiveDocument.AttachedTemplate
        'Check each building block entry in the attached template
        For i = 1 To oTemplate.BuildingBlockEntries.Count
            'Look for the building block name
            'and if found, insert it.
            If oTemplate.BuildingBlockEntries(i).Name = strBuildingBlockName Then
                oTemplate.BuildingBlockEntries(strBuildingBlockName).Insert _
                        Where:=Selection.Range
                'Set the found flag to true
                bFound = True
                'Clean up and stop looking
                Set oTemplate = Nothing
                GoTo lbl_Exit
            End If
        Next i
    End If
    'The entry has not been found
    If bFound = False Then
        For Each oAddin In AddIns
            'Check currently loaded add-ins
            If oAddin.Installed = False Then Exit For
            Set oTemplate = Templates(oAddin.path & _
                                      Application.PathSeparator & oAddin.Name)
            'Check each building block entry in the each add in
            For i = 1 To oTemplate.BuildingBlockEntries.Count
                If oTemplate.BuildingBlockEntries(i).Name = strBuildingBlockName Then
                    'Look for the building block name
                    'and if found, insert it.
                    oTemplate.BuildingBlockEntries(strBuildingBlockName).Insert _
                            Where:=Selection.Range
                    'Set the found flag to true
                    bFound = True
                    'Clean up and stop looking
                    Set oTemplate = Nothing
                    GoTo lbl_Exit
                End If
            Next i
        Next oAddin
    End If
    'The entry has not been found. Check the normal template
    If bFound = False Then
        For i = 1 To NormalTemplate.BuildingBlockEntries.Count
            If NormalTemplate.BuildingBlockEntries(i).Name = strBuildingBlockName Then
                NormalTemplate.BuildingBlockEntries(strBuildingBlockName).Insert _
                        Where:=Selection.Range
                'set the found flag to true
                bFound = True
                GoTo lbl_Exit
            End If
        Next i
    End If
    'If the entry has still not been found
    'finally check the Building Blocks.dotx template
    If bFound = False Then
        Templates.LoadBuildingBlocks
        For Each oTemplate In Templates
            If oTemplate.Name = "Building Blocks.dotx" Then Exit For
        Next
        For i = 1 To Templates(oTemplate.FullName).BuildingBlockEntries.Count
            If Templates(oTemplate.FullName).BuildingBlockEntries(i).Name = strBuildingBlockName Then
                Templates(oTemplate.FullName).BuildingBlockEntries(strBuildingBlockName).Insert _
                        Where:=Selection.Range
                'set the found flag to true
                bFound = True
                'Clean up and stop looking
                Set oTemplate = Nothing
                GoTo lbl_Exit
            End If
        Next i
    End If
    'All sources have been checked and the entry is still not found
    If bFound = False Then
        'so tell the user.
        MsgBox "Entry not found", _
               vbInformation, _
               "Building Block " _
               & Chr(145) & strBuildingBlockName & Chr(146)
    End If
lbl_Exit:
    Set oTemplate = Nothing
    Set oAddin = Nothing
    Exit Sub
End Sub