Hi and thanks for your question. I am reading it as two parts:
1. How to transfer or redirect calls from UCCX to CUC voicemail
To do this, you will need to make sure your CTI Ports (aka Call Control Group) has a CSS which can reach the Voicemail Pilot number. Then, you will use the Call Redirect step in your script, with a destination of the VM Pilot number, while providing the mailbox or call handler extension as the Called Address Reset To (you can use a String variable or just type it in, in double quotes Ex. "4005")
This next part is not necessary for the transfer or redirect to work, but it does help keep reporting clean. You will want to place a Set Contact Info step inside the Successful branch of the Call Redirect step to mark the Contact as handled. After the Set Contact Info step, place and End step to end processing of the script.
Lastly, you'll want to engineer scenarios for failures: Busy, Invalid, and Unsuccessful. Sometimes it's appropriate to just End the script, which will play the Application Default Script, which if set to the default, will simply say "I'm sorry, we're currently experiencing technical difficulties..." Which you are this point.
2. How to check the status of Agents for a given CSQ from within a UCCX Script
For this, you will need to use the Get Reporting Statistics step and set it up to read the various statuses you want. E.g., Resources Not Ready, or Logged In Resources, etc.
Then, once you have the metric in your integer variable, you would use and If step to test the condition of the value. Eg., If (logged_in_agents == 0) OR If (ready_agents >= 3) etc. If would then be in the True or False branch that you'll place your above Call Redirect step to redirect the caller to voicemail.
Whether you place your Get Reporting Statistics before, inside of, or after the Queue Loop, is a design preference, and should really be discussed with the business.
I hope that helped.
