I wrote this Python script as a "bridge" to generate a fake `.aux` file for use with xcite and Biblatex. It is a very crude attempt, but it worked for the case I needed it for. Run it as `python gen_dummy_bib.py document.bbl document_fake.aux`

gen_dummy_bib.py

import sys
import re

replace_count = 1
infile = open(str(sys.argv[1]), 'r')
outfile = open(str(sys.argv[2]), 'w')

for line in infile:
    if '\\entry' in line:
        outfile.write(re.findall('\\\\entry\{[^{]+', line)[0].replace('entry', 'bibcite') + '{' + str(replace_count) + '}\n')
        replace_count += 1

infile.close()
outfile.close()