Set another application's top, left, width and height from my app?

You can call explorer.exe with
......Place ShellAPI in Form Uses Clause
ShellExecute(Form1.Handle, 'open', 'c:\windows\explorer.exe',
  '', 'c:\temp', SW_SHOWNORMAL);
However, you can't set placement parameters with this call.
One possibility would be to surf for explorer like component on internet and just call it up in a window. Good luck.

hmmm
the user may change the current folder, so I will still need to kep track of it
If I create an explorer, then use 1 of the methods above to get it's handle straight away.
I store that handle.
WIll that handle remain constant even if the user changes the current folder in that explorer?

Yes...

ok, I can now get the correct list of "explorer windows"
however, when I try to bring them to the front, and set their position, sometimes it is not working
if i try again, it may/may not work. This is intermittent, but a pain
I'm using the following method since I am holding the window handles in a list
     SetForeGroundWindow(H1);
     SetWindowPos(H1,HWND_BOTTOM,10,10,400,300,0)

I've added checks for "IsIconic() and IsZoomed()" but still sometimes it does not bring the window to front and set it's dimensions. sometimes it does though...
Is there a way to make ths reliable?
Thanks, Loki

thanks guys. points split because there was some useful information in many answers