C++ program service - c++

Question

I have a personal server and I want to add some new functions to it.It is a Windows server running Windows Server 2019.The core program is wrote by me in c++,but it is just a core and can't access the Internet.It should receive a string from a webpage and return a string to it.My old way is using ASP create a file to storage the string from webpage and use my c++ program to overwrite it.But if the server get two tasks at same time,the result will become a mess.My ISP blocked port 80 so I'm using port 8012 to run my website.My router can't map to many port outside (There also a FTP service and a mail service in the server.) so I can only use the port 8012.What should I do?Should I write a C++ HTTP server?
Server Info:
Service port-inside port-outside software
WEB 80 8012 IIS
FTP 21 21 Serv-U
FTP-pasv 6000-6009 6000-6009 Serv-U
POP3 110 9110
SMTP 25 9025
RemoteDesktop 3389 3389 Windows

Answer 1

I have solved my questions.I am using some AJAX code to add a time sign and random numbers to avoid request crash.
Here are the AJAX code:
function GetValue(id)
{
return document.getElementById(id).value;
}
function SetValue(id,val)
{
document.getElementById(id).value=val;
return;
}
function GetTRValue() //Time-Random value,avoid messing up request
{
var rdm=Math.Random().toString(16);
var dt=new Date();
var time=dt.getTime().toString(10);
var tr=rdm+time;
return tr;
}
function EncodeRequest()
{
var req=new XMLHttpRequest();
req.onreadystatechange=function(){
if(req.readyState==4 && req.status==200)
{
SetValue('code',req.responseText);
}
else if(req.readyState==4 && req.status!=200)
{
alert('Server error:'+req.status);
}
}
req.open('POST','/base/base.asp',true);
req.setRequestHeader('Content-type','application/x-www-form-urlencoded');
req.send('type=encode&code='+GetValue('base')+'&srcstr='+GetValue('str')+'&rdm='+GetTRValue());
return;
}
function DecodeRequest()
{
var qer=new XMLHttpRequest();
qer.onreadystatechange=function(){
if(qer.readyState==4 && qer.status==200)
{
SetValue('str',qer.responseText);
}
else if(qer.readyState==4 && qer.status!=200)
{
alert('Server error:'+qer.status);
}
}
qer.open('POST','/base/base.asp',true);
qer.setRequestHeader('Content-type','application/x-www-form-urlencoded');
qer.send('type=decode&code='+GetValue('base')+'&srcstr='+GetValue('code')+'&rdm='+GetTRValue());
return;
}
In my ASP file,I simply create a folder named the "Time-Random Value",and put request file here.Then wait for responses from C++ program,read it and delete the folder.
In my C++ program, I scan for folders and write responses into the same folder.