CTIOS is for UCCE only not UCCX.
For UCCX, you could develop a Bridge Mode client using UCCX CTI protocol. you only get the agent’s CSQID (queue) on the agent state Talking event not on the call events.
If you have further questions about UCCX CTI protocol, post them in the forum here
https://communities.cisco.com/community/developer/collaboration/contact-center/express-cti
The tech center for UCCX CTI Protocol is here
https://developer.cisco.com/site/collaboration/contact-center/express-cti/overview/