Getting substring by regex

[Christine Mayer]

Hi, I got a String that is composed of digits, white space, numbers
and other characters.
Example: 03... London (first two digits of post code, plus 3 dots for
the remaining digits).

I want to go through the String and search for the first occurrence of
a letter (A-Za-Z).
Then I want the String from this point on, excluding the "post code
String" containing only numbers, whitespace and dots.
The class String seems to have a "split(regex) function, but this
didn't work for me.

Any idea how this could be done?

Thanks in advance,