Windows equivalent of the Linux command 'touch'?

What do you use when you want to update the date-modified field of a file on Windows?

1. commands accessible via C++, .NET, C#, or something native to Windows (Vista preferably)
2. tools/applications preferably free, and if possible open source as well

Edit: there is already a page for applications as pointed out by CheapScotsman here.

If anyone knows how I can do this via C++, C#, WSH or something similar, well and good, else I would think everything else is covered in the linked question.