RPGLE pgm to parse a string

["Stiju Easo" <stiju.as400@xxxxxxxxx>]

I have a varible length string, which i should parse for charecter '_' from
end of it,
 Can any one help in this?

None of the parsed parts are fixed length,

I want to know how can i 1) reverse the string,
                                     2) Read charecter by charecter
                                     3) add seperated charecter to form a
new string.