I assume you want to generate load combinations automatically. If so I can think of three options:
1. Modify the regulation file and generate either automatic code combinations or manual combinations
2. Generate automatically manual combinations according to the regulation file as it is and then edit the combinations changing the load factors for dead loads in the combination table.
3. Generate automatically manual combinations according to the regulation file as it is.
Create additional manual combination which includes all dead load cases with negative factor (assuming that the load factor for dead loads is e.g. 1.2 the negative factor will be -0.2)
Add this new combination to the automatically crated ones
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Artur Kosakowski