User access to only specific subdirectory

is is possible to grant user access to only one subdirectory? example

a. create ftp user with read/write/delete access (ftp user doesnt belong to uguys group)

$ cd /etc/mydir
$ls
file1   file2
$ls -al
-rw-rw-r-x   2 unixguy  uguys  96 Dec 8 12:53 file1
-rw-rw-r-x   2 unixguy  uguys  96 Dec 8 12:53 file2

Solution I guess is create username ftp under another group and chnage the permission like chmod o+w file2 and chmod o+w file1. Is there a way to have ftp user to only access file1 and file2? No other file in the whole OS?

thanks,