Regex substitution trouble

[massi_srb at msn.com]

Hi everyone,

I'm not really sure if this is the right place to ask about regular expressions, but since I'm usin python I thought I could give a try :-)
Here is the problem, I'm trying to write a regex in order to substitute all the occurences in the form $"somechars" with another string. This is what I wrote:

newstring = re.sub(ur"""(?u)(\$\"[\s\w]+\")""", subst, oldstring)

This works pretty well, but it has a problem, I would need it also to handle the case in which the internal string contains the double quotes, but only if preceeded by a backslash, that is something like $"somechars_with\\"doublequotes".
Can anyone help me to correct it?

Thanks in advance!