how to obtain the aux file of the references

[Wolfgang Engelmann]

I use a bib file from which I select the references for my document. 
Since I use only parts of the references, I would like to get those by 
using the aux file which is produced if I export the latex file and run 
this (3 times, and onces biblatex). In JabRef, which is my reference 
manager, I can (under tools) select a subfile based on this aux file. 
Can I get the aux file somehow also without the latex procedure from lyx?

Wolfgang