You are going to have to do a lot of hand calculation for this one. I suspect that, if your pipe is full of liquid, you will have to account for axial strains (that CAESAR II ignores) in your support design.
Other than that, I don't see why the methodology of BPVC Code Case N-392-3 would not apply. You will obviously have to either glue on lugs or trunnions to your riser in order to support the weight; friction just isn't going to hold it up.
If possible, can you "stair-step" your riser, where you put in a little offset at several different elevations to avoid the long vertical run? This will make the support design a whole lot easier (but may aggravate your process engineer and plant layout guy).
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CraigB