for i = 1 to 10, or while (is there an equivalent?)

Hi,
 
I'm probably going about this the wrong way, but I have a C string in a
variable that I want to escape the backslashes and double-quotes prior to
output.  ie. foo\bar"xxx -> foo\\bar\"xxx
I figured I could use the XPath contain and substring functions to do what I
want, but I can't find a way to iterate until there are no more characters
of interest.  Can this be done in XSL/XPath?
 
Regards,
 
Steven