Yet another try.

I have some local footnotes (conversion = character) and would like to reset  set the counter  
(a) to “a” and 
(b) to a specific value other than “a”. 
How can I do this?

re (a) 
\resetnumber[localfootnote] does not work. 
	! Missing \endcsname inserted.
<to be read again> 
                   \numberlocalfootnotenumber 
\setcounter #1#2->\@EA \xdef \csname #1
                                       \endcsname {\the \numexpr #2\relax }
l.217 \resetnumber[localfootnote]

Am I even right to assume that there is a pre-defined localfootnote counter?

Alan