I am including, using the enumerate environment, some sections from legislation.
In legislation, it is common to indicate subsections which were added later through the use of letters. So, for example, we might have:
5 Awesome section
(1) This subsection existed from the beginning.
(1A) This subsection was inserted later.
(2) And we continue with the original Act
I'm having trouble inserting '(1A)' as an enumerate counter.
When I use the enumerate package, and do:
\begin{enumerate}[(1A)]
the package appears to treat 'A' as the counter, and outputs '(AA)'.
When I try to use setcounter, as in:
\begin{enumerate}
\setcounter{enumi}{1A}
I get
! Package calc Error: `A' invalid at this point.
How can I insert (1A), or similar letter number combinations, as an enumerate counter?
I'm not awfully fussed that it actually count correctly; I'm just after identical formatting to a normal enumerate environment.

1Anot rather a sub-enumerate environment, although one should not use lists with just one entry. If there are more of them however, I would use\begin{enumerate}again to indicate the additions, with some redefined counterenumii– Jun 09 '14 at 09:45setcounter{enumi}{1A} with a non number argument. And it is\labelenumi` you have to change – Jun 09 '14 at 09:46