function _RegisterComServer (DLLName: string): boolean;
type
  TRegProc = function: HResult; stdcall;
const
  RegProcName = 'DllRegisterServer'; { Do not localize }
var
  Handle: THandle;
  RegProc: TRegProc;
  FullPath: string;
begin

  if ExtractFilepath (Fullpath) = '' then
    Fullpath:= ExtractFilepath (ParamStr (0)) + Fullpath;

  if AnsiTextPos ('.DLL', Result) = 0 then
    Fullpath := Fullpath+ '.DLL';

  Handle := SafeLoadLibrary (Fullpath);
  if Handle <= HINSTANCE_ERROR then
    Result := False
    else
    try
      RegProc := GetProcAddress (Handle, RegProcName);
      Result := Assigned (RegProc);
      if Result then
        Result := RegProc = S_OK;
    finally
      FreeLibrary(Handle);
    end;
end;

function _LoadTypelib (DLL_TLB_Name: string; out tlib: ITypeLib): HResult;
var
  str: PWidechar;
  size: integer;
begin

  size := (length (DLL_TLB_Name) + 1) * 2;
  GetMem (str, size);
  try
    StringToWidechar (DLL_TLB_Name, str, size);
    Result := LoadTypelib (str, tlib);
  finally
    FreeMem (str);
  end;
end;

function _UnRegisterComServer (DLLName: string): boolean;
type
  TRegProc = function: HResult; stdcall;
const
  RegProcName = 'DllUnregisterServer'; { Do not localize }
var
  Handle: THandle;
  RegProc: TRegProc;
  FullPath: string;
begin
  if ExtractFilepath (Fullpath) = '' then
    Fullpath:= ExtractFilepath (ParamStr (0)) + Fullpath;

  if AnsiTextPos ('.DLL', Result) = 0 then
    Fullpath := Fullpath+ '.DLL';

  Handle := SafeLoadLibrary (Fullpath);
  if Handle <= HINSTANCE_ERROR then
    Result := False
    else
    try
      RegProc := GetProcAddress (Handle, RegProcName);
      Result := Assigned (RegProc);
      if Result then
        Result := RegProc = S_OK;
    finally
      FreeLibrary(Handle);
    end;
end;