st: two-digit string variables

[Alejandro Delafuente <alejandro.delafuente@st-antonys.oxford.ac.uk>]

Hi statalisters,
I have a string variable with two-digit and one-digit values. How can I tell 
Stata to place zeros before those one-digit values so that I end up with two 
digits in all cases always. For instance,
x          x(desired)
34           34
3            03
25           25

Many thanks for any help!

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