How can I interpret the circuit of the voltage probe with cable between the probe body and the compensation box?
It is most straightforward to just treat the cable as a parallel capacitance rather than a terminated line.  The capacitance of coax will be in the range 20-30pF/ft.
That is a about 90pF for a 3 feet cable.  This will appear in parallel with Cc. Cp will need to be correspondingly larger to compensate the network.

In reality the cable is not made as a normal coax, it often uses a very fine gauge resistance wire as the centre conductor to reduce the capacitance and also to minimize resonances.

Also in real scope probes intended to have 100 MHz of bandwidth or more there will be  number of other small inductors and capacitors to equalize the response at high frequencies.

This is an old but very good document from Tektronix Circuit Concepts series describing scope probe circuits. Oscilloscope Probe Circuits

EDIT:

At low frequencies where the wavelength is large compared to the length of the cable the cable can be treated as a lumped element model.

With high system impedances and moderate frequencies the inductance component can ignored. Typically real scope probed will use resistance wire as the center conductor to minimize any resonances caused by the cable inductance.