A 'fixed Random number' node in Cinema 4D Expresso

I need to generate random numbers for several objects. I am using this in a scene for offsetting textures automatically, in my 'procedural audience'-setup. I want every ring of audience to use the same texture, but it has to look a bit amorph, so I need each ring's texture to be offset randomly. The subsequent rings cannot be generated by a MoGraph-cloner, since the rings are not scaled, but the radius is actually increased, and the texture is tiled more often, the bigger the ring gets.

Cinema 4D's Expresso random node is somewhat limited: it only allows us to generate a random number each frame, but we need it only once. The number must be generated and then stay the same forever, even when we save and reopen the scene. It has to work like the Random Effector of MoGraph, when the noise is not animated.

Hopefully Maxon can give us this feature as an addition to the Random node, or in a new node.