st: How to get rid of leading and trailing letters and symbols?

[Ekaterina Hertog <ekaterina.hertog@sociology.ox.ac.uk>]

Dear All,
I have got a dataset where the id variable is a part of a web-link. It 
can contain letters followed by the id number: (e.g. 
/profile/?id=9596986) or it can contain the id number in the middle 
(e.g. /profile/?id=9591886&reftype=detail). I need to create a variable 
which will only contain the number that is part of the id variable. I 
also need to be able to distinguish between the cases where the number 
is trailing vs. cases where it is in the middle. I looked at the advice 
available on removing leading or trailing 0s in Stata 11 
(http://www.stata.com/support/faqs/data/leadingzeros.html), but in my 
case I cannot actually specify the letters and symbols that lead or 
trail so I am stuck. I use Stata 11.
Any advice will be very much appreciated,
Ekaterina

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