@Nexern: I think that's a great way to handle passwords

Agree with NxtChg about the separator, just fix it as a character never used in the suffix (having one less char to use is no big deal), this should be clear enough. This reduces the burden of having to remember what the separator was, in case folks have to reformat and reinstall the client (consequently wiping all settings) or something. Alternatively, just include the separator in the suffix and save it to file.
EDIT: Use the password as one seed for the suffix, and save the separator and other seed to file. This should gives free encryption for the suffix file (assuming secure choice of generating algo).