The trick that converts the '::' into directory separators (as well as assuming a '.pm' extension) only works on barewords.
So you will need to specify the directory and filename explicitly.

Update: Looking at the other answers, I guess I was wrong. :-)
Update 2: Excepting tadman's suggestion (using 'eval'), according to perlfunc at least, I was right. I just gave up too easily. :-)

Impossible Robot