There are two points to consider here:

1) Piping programs, such as CAESAR II, utilize the 3D Beam Element. As such, you can't ask these programs to evaluate behavior that is beyond the capabilities of this element - small deflections, small angles, dominated by bending. You can't model a flexible hose with a 3D beam element.

2) The stiffness of the flexible hose is so much less than that of the pipe, it (the flexible hose) has no effect on the pipe system. Therefore, you can model the system up to the pipe/hose connection, and stop. The pipe has essentially a free end.

If you are concerned about the behavior of the flexible hose, you will need to consult the hose manufacturer for details and recommended practices. You can not evaluate flexible hose in CAESAR II.