STAAD: How to Implement concrete cracked section on Shear walls modeled as Surface Element

Good morning,

ASCE 7-10, Section 12.7.3 requires that stiffness properties of concrete elements shall consider effects of cracked section. I understand that one way to do this is use an E (modulus of elasticity) with reduction factor. However, my understanding is that "cracked section" must be considered only when running a seismic load case/combination. So how do I specify in STAAD to use a "reduced E" when running a seismic combination and a "unreduced E" when running a non-seismic combination? I would appreciate the quick response.

Thanks,

Dennis