Quoting message received from Yoder, Alan:
The filer's CIFS implementation follows symlinks within the same share, and if you use widelinks, across shares. This is transparent to the CIFS client except for a DFS redirection in the case of a wide link.
For a Windows-side tool that can set Unix symlinks on machines running Data ONTAP, contact your SE.
A working ln function in your jsh might not make it in the feature request list for Ontap?