Question about Script Force Field

Dear all,
I want to revise the dreiding force field by adding a threshold value of chemical bonds in my system. When the forces of chemical bonds are larger than threshold value, the chemical bonds will be broken. The threshold values of different chemical bonds are given by reactive force fields. How to do it? How can I check the script file of existing force fields (such as dreiding and Reaxff)in material studio? Thanks.
Best regards,
Yours
CHENG Xu