pulldata() cannot be used for this purpose - it is only used for reading in data from CSV files attached to your form; hence the error message you see.
Can you perhaps describe exactly what you are trying to accomplish here:
I need to capture the surveyor’s name from the URL
But the URL doesn’t intrinsically contain the surveyor’s name… 
What you might try instead is to prefill the desired field in your form by adding a query parameter (with the surveyors name?) in the URL; this provides a good description of how this works: Prefill fields via URL in Enketo - #4 by knoxjohnny
