reference to objects

Hi,
is there a way to reference to a data object without copying it?

For example I have a huge matrix called dist and I want two objects
obj1 and obj2 to have a memeber dist that points to the matrix, but
I don't want, for memory reasons, to copy the matrix twice.

As far as I understand the following code will generate three copies
of my data:

dist <- some_code_that_generates_data
obj1$dist <- dist
obj2$dist <- dist

Thank you!
Giampiero