REST API consumption via JavaScript user credentials security question

Summary

Account sessionis REST API URL parameter authorization via JavaScript Desktop Integration - exploring a possilble solution

Content

Hello,

I'm hoping someone can point me in the right direction on this.  I'm in the process of writing what would seem as a quick 'Connect Desktop Integration' JavaScript for one of our work spaces currently deployed only on the Agent Desktop Client, but have ran into a bit of a challenge. 

There are four Custom Object 'Menu' type fields on this workspace and depending on the value selected in any one of the four fields, the said value should be copied in real time to a 'Text Field' also on this workspace.  Since these menus are custom fields, the 'GetNameValues' method of retrieving the menu XML structure and parsing for the value does not seem applicable.  I'm basing this on what I have already tired and documentation found here: