Programmatically Add existing project to the current solution

Hi Folks,

I am working on multi project template. I want to add existing project to current solution(dte,solution)

I tried dte.Solution.AddFromTemplate function,it works fine, If i want to add exisitng project to a new folder in a solution.

My requirement is to add existing project to existing folder in the solution,not to create new folder.

When I tried pass existing folder path to  dte.Solution.AddFromTemplate, it throws an error saying Destination folder already contains file and folders.

Any work around to do this??

if not,how is the idea of adding existing project to new folder and move it to desired folder in a solution..For this I need to get the newly added project to the solution.

However dte.Solution.AddFromTemplate returns null.

Any reference to work on it would be helpful

Thanks

Qureshi