A quick way of opening any file with given extension within a directory hierarchy?

[Enselic]

Hello

I am wondering if this functionality has been written by someone.

1. I call func-i-look-for.

2. The mini buffer switches to "What file do you want?: "

3. When I start typing, there is a buffer that shows all files within
a given directory hierarchy whose filenames start with what I have
written.

4. I can cycle between available completions with C-n C-p (without
messing up what I have written in the minibuffer) and <return> takes
me to chosen buffer.

Let's clarify with an example. I have the following source tree:

root/file.cpp
root/gtk/gtk.cpp
root/msw/file2.cpp

And call (after requred setup is made) func-i-look-for, then type "fi"

I would now have file.cpp and file2.cpp listed in the buffer, and C-n
<return> would get me to file2.cpp.

Does anyone know if there is elisp code that does this somewhere?

Thank you,
- Martin Nordholts