Do you want to exclude numbers and spaces at the start of paragraphs? I assume that you want to keep numbers that might pop up inside paragraphs? Like "India gained independence in 1947".
I think it might be easier to select what you don't want and then remove it.
Select anything that is not an letter at the start of a paragraph with this expression:
YES IT USE
i missout this reg
Nothing wrong with this one:
The word-breaks (\b) at the beginning and end ensure only whole words are taken. You probably also want to allow for hyphens; in that case use something like
which (if I'm correct) will match the middle of
"412 red-and-blue socks went missing in 1948"
without the numbers and spaces at either end.