Macro Certificates for Local use

I have written an Excel application in VBA and need to have my coworkers access it regularly. However, they have to set the security to low or medium to use the macros I've created. Is there any way to create a local certificate for my coworkers so the medium security does not open the disable/enable window, and high security does not block the macros. Our IT guy insists that no one run on low security, and would prefer to see us all use high security.

Can anyone point me in the right direction

Thanks,

Paul