string mystring="♫♠~.┘&╤+@\????v?*=?\n?E???M???u??????r[?????o?W,~ ?:";
string test="";
char[] allowCharacter = new char[] {' ','@','\n','\r','.',':','[',']','/','*',';','=','-','"','?','+','$','!','~','#','^','&','(',')','_','-','>','<','!','`', '{','}','|'};
foreach (char item in mystring)
{
if (allowCharacter.Contains(item) || char.IsLetter(item) || char.IsNumber(item))
{
test = test + item.ToString();
}
else
{
test = test + ".";
}
}