This support KB article will show the following example on how to setup a category routing based on a UDF value “Blanket PO”
Pre-requisites:

1. Knowledge of how to create a user defined field and mapping it to a document type (ENC or API)
   
2. Knowledge of how to modify existing workflow routing to include a category routing
   
3. Knowledge of how to setup routing categories

Microix Help Desk - How to route documents based on UDF Lookup Value - Knowledge base