Ok, say you have the following numbers:
Desk: 1234
Cordless: 2468
Mobile: 5678
Assistant: 4321
Voicemail: 121
Now say you decide you want to have it so that when someone dials your desk phone and you want it to ring your desk phone first for 7 seconds, then try your cordless for 7 seconds, then your mobile for 10 seconds, then if all else fails go to your voicemail.
You would do the following to set this up:
CDINE

IR=1234; <---Remove any existing diverts
PELPI

IR=1234,CHO=1,ANSPOS=1234,TIME=7,BSYCHO=2; <---When caller rings 1234, ring 1234 for 7 seconds, if busy or no reply, go to CHO=2
PELPI

IR=1234,CHO=2,ANSPOS=2468,TIME=7,BSYCHO=3; <---Same again, hop onto CHO=3 if busy or after 7 seconds
PELPI

IR=1234,CHO=3,ANSPOS=5678,time=10,BSYCHO=4; <---And again, you will have to make sur that the time value is shorter than any voicemail you have already setup on your mobile
PELPI

IR=1234,CHO=2,ANSPOS=121; <---Final destination, voicemail
The above is called IRD (Individual Repeated Deflection), but if the licences are available you can have up to 5 lists with different versions of the above, which is known as a Personal Number.
To use the above you would do *10*1# to turn on, and #10# to turn off. If you used Personal Number you would substitute the 1 in the above code to whichever list you wished to enable.
Hope this helps.