Is it possible to have ';' not delimiting comments only when it is on the right hand side of an equal side?

I have the following INI file:

; some comment that should be ignored

[section]

key=value1;value2;value2

With the following code, Nini is removing value2;value3 as it is regarded as a comment:

            using (TextReader tr = new StreamReader(iniFile))
            {
                IniDocument doc = new IniDocument(tr);
                foreach (DictionaryEntry entry in doc.Sections)
                {
                    string key = (string)entry.Key;
                    IniSection section = (IniSection)entry.Value;
                    if (section.Contains("key"))
                    {
                        // ... do stuff
                    }
                }
            }

Of course, I can do something like

IniReader ir = new IniReader(tr);
ir.SetCommentDelimiters(new char[] { '!' });
IniDocument doc = new IniDocument(ir);

but then also the initial comment will be treated as a config file and result into an error ("expecting =").