Multidimensional arrays in Korn shell

Hello,
How do you implement multidimensional arrays in Korn shell. I have to implement popd and pushd in ksh, and I'm thinking about implementing them with arrays. I want to have an inode-like structure for the stack (in case you have more than 1024 directories).
Thanks,
Yasir

Ok, there are no multidimensional arrays. Is there a built in way to count the number of words in a string?

Here's one way...
echo $string | wc -w

Thanks, but is there a shell built-in that would do the same? I would perfer not to fork another process to determine the number of words.