Hi Greg,
The way I have had to solve this for other customers is to set the Folder Permissions and Share Permissions to Everyone - Full Control for direct access from MII. Another option may be to use the PCo FileMonitorAgent and agent instance and write the file with a TagQuery, setting TagName=fully qualified path/file name, and TagValue=the text of the file. PCo Agent can specify authentication user to be used to access Remote Shares. I have not tried this so I am not positive that it will work.
Regards, Steve