what is the root/access object for your service request creation page ?
you need to check whether BTREFOBJ is already there or not (created/not created). if is there, then you can get the object by using some relations and set the object id
else you need to create that object using relations and create related entity method and set that property with object ids that you have.
basically you need some basics in BOL.
let me know if you need more help.