You could use the method of NSString substringWithRange
Example
NSString *string=@"hi how are you";
NSRange searchFromRange = [string rangeOfString:@"how"];
NSRange searchToRange = [string rangeOfString:@"you"];
NSString *substring = [string substringWithRange:NSMakeRange(searchFromRange.location+searchFromRange.length, searchToRange.location-searchFromRange.location-searchFromRange.length)];
NSLog(@"subs=%@",substring); //subs= are