semantic-subst-char-in-string
semantic-subst-char-in-string is an alias for `subst-char-in-string' in `fw.el
'.
(semantic-subst-char-in-string FROMCHAR TOCHAR STRING &optional INPLACE)
Replace FROMCHAR with TOCHAR in STRING each time it occurs.
Unless optional argument INPLACE is non-nil, return a new string.