I am assuming by ILD load you mean a displacement controlled load. We do support these through what we call Joint Deflections in Precede under Load > Elements > Joint Deflection, or JOINT PERSET in the SACS IV documentation. Note that the joint preset line will fix the degrees of freedom which are deflected so no additional deflections in those degrees of freedom are possible.
If you are referring to moving loads as in loads which move along the length of a member, those are supported by the MOVLOD, MOVGRP and MOVSTP lines in the Seastate manual and can be defined using Environment > Misc > Moving Load Condition. See section 126.96.36.199 of the Seastate manual for more information.