Hi Ben,
Yes, it is possible. Check out the below blog I wrote, go through the whole thing so you understand the concept and idea behind the trick.
Accurately positioned Custom Comments in Column Charts
In Step 1, variable v_LinesToSkip, I'm calculating the vertical position of the comments dynamically, which can help you calculate the height of the cell. And for the width of the cell, replace with one of two spaces instead of char(13).
Let us know if you've any issue.
Thanks,
Mahboob Mohammed