Dear @gamze,
Thank you for your question. First, are you interested in the exact value of the mass attenuation of photons in lead? If so, I propose you have a look at the following post where this value is calculated for lead. I can provide some support with the user routines in case you are not familiar with them.
On the contrary, if you want to study the impact of certain lead geometry on the flux of photons, among others, you can use the approach of the file. Essentially, you obtain the output of the USRBDX card, showing the differential fluence of photons as a function of the energy and the solid angle in the interface between two regions. The tab file includes the angle-integrated fluence data as a function of the energy only. However, retrieving the mass attenuation from this may be not simple.
Please let me know if this is helpful.
Best regards,
Mario