unusual exponential formatting puzzle

[Neal Becker]

Like a puzzle?  I need to interface python output to some strange old
program.  It wants to see numbers formatted as:

e.g.: 0.23456789E01

That is, the leading digit is always 0, instead of the first significant
digit.  It is fixed width.  I can almost get it with '% 16.9E', but not
quite.

My solution is to print to a string with the '% 16.9E' format, then parse it
with re to pick off the pieces and fix it up.  Pretty ugly.  Any better
ideas?