Cannot Convert Rule For Use on OpenCL

[thapco4]

Is there any way to get the "using p (nth character) with positional rules" to work?
example substitute 2nd occurrence of 's' with '$'.
the rule should use the -j option then use something like "%2c Dp ip", but I keep getting the cannot convert rule error no matter how I try to change this around.  
Also, I am trying to incorporate this into a rules file for multiples, the above was just one example.

[Snoopy]

Is there any way to get the "using p (nth character) with positional rules" to work?
example substitute 2nd occurrence of 's' with '$'.
the rule should use the -j option then use something like "%2c Dp ip", but I keep getting the cannot convert rule error no matter how I try to change this around.  
Also, I am trying to incorporate this into a rules file for multiples, the above was just one example.

short answer no

there is no logic build in for this approach, substitutions allways change all chars, if you you need this, use a simple script language like python and something lik string.replace('ss'. s$) or a more complex functions for words like Susan -> Su$an