selective increment numbers in substitute

Hi,

I want to selectively increment numbers in substitute.
I'm familiar w/ submatch for increment all numbers in substitute, like in vis. mode range:
'<,'>s/\d\+/\=submatch(0)+1/gc

But what if I want to increment numbers only of lines containing a preceding pattern, say "Number".
For instance:
"
1
Number: 2
"

Should change to:
"
1
Number: 3
"

TIA,
Thanks!
Yosi

--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

---
You received this message because you are subscribed to the Google Groups "vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vim_use+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.