It's possible to use ClearCase's Context Menu Editor on Windows to
add menu entries for Windows Explorer and/or ClearCase Explorer.  The
most useful example I know of is adding a "Recursive Add to Source
Control" right below the standard "Add to Source Control" entry.  This
is simply a shortcut to the "mkelem -recurse" feature implemented in
ClearCase::Wrapper. See WinRecMkelem.gif and WinRecMkelem.reg for more
details. If you're familiar with Context Menu Editor these (especially
the picture) should be pretty much self-explanatory.

Don't apply the WinRecMkelem.reg directly, though. I don't know whether
that works. It's just there for reference. You should be able to
generate similar entries for your site easily using the Context Menu
Editor as shown by the .gif picture.