coverting "." serparated string to an array ?

[PHPycho]

Hello forums!
Suppose we had list of strings in an array in a hierarchical form(separated by ".") as follows:
FOLDER1
FOLDER1.subfolder1
FOLDER1.subfolder2
FOLDER1.subfolder2.sub_subfolder1
FOLDER1.subfolder2.sub_subfolder12
.. can go upto n levels
FOLDER2
FOLDER2.subfolder1

I want to convert such string in an array , For example
array("FOLDER1" => array("subfolder1", "subfolder2" => array("sub_subfolder1","sub_subfolder12"), ...), "FOLDER2" => array("subfolder1"), ...etc)
How to accomplish this as it seems to be recursive.
Thanks in advance for the valueable tips and suggestions.

[Habtom]

Hi PHPycho, were you able to solve this?