Numbering Style in word

[shaharwaserman]

Hello, and thanks in advance for the assitance
I wish to change the numbering style..... but not to one of the preset styles.
I mean I want to create a numbered list which goes: 10, 20, 30, ......
when I try to set it manually and delete a line.
for example:

I start with:
10
20
30
40



and I delete the line with the 30, the line with the 40 instead of changing to 30 is changing to 39 (because the numbering style is 1,2,3,...)
is there a way change that and retain a list which jumps 10 numbers each time ???