How to programmatically add a sequence file to a project

Hi,
Using Teststand C++ API, I would like to add a sequence file to the current project in the current workspace.

My sequence file has been created using engine->NewSequenceFile(); and saved in the path "Path" (as std::string).
I try to create a new workspace file this way :

engine->CurrentWorkspaceFile->GetRootWorkspaceObject()->NewFile( _com_util::ConvertStringToBSTR(Path.c_str()) );

But this line throw a com exception "Unknown error 0xFFFFBC63" which should correspond to error -17309

What is the correct way to do this ?

Thank you.