How to build a gui program that locks an exe file with given password by user

From the context, I understand that we are talking about Windows EXE programs that are to be protected with a password regardless of their location and computer.

This would result in the following requirements:
1. creating password protection for Windows EXE-programs with a GUI-based program

Some questions arise that are not yet clear:
- Where should the password be stored?
- Should the password be changeable?
- Should both 32 and 64 bit programs be protected?

2. when the protected program is started, a GUI-based form should be displayed that only allows the program to be started if the correct password has been entered.

One possibility would be to convert the exe file into hex code with a tool and to start this image in a launcher via system calls.

So you need at least one program that contains the launcher and the image and queries and checks the password. A second GUI program that conveniently automates the creation of the starter would be nice for reasons of convenience, but is not necessary for the time being.

A technical solution for a launcher was mentioned here, for example:
https://www.codeproject.com/Answers/5377359/Problems-with-converting-runpe-Cplusplus-to-vb6
(or in the original: https://github.com/Zer0Mem0ry/RunPE/blob/master/RunPE.cpp)
The function RunPortableExecutable() realizes the start of an exe file converted into hex code.

Note: If you store the password in the starter, you would have to protect it and it would be difficult to change.

An interesting project, but as Richard has already indicated, it requires some knowledge and time.

For the implementation of the (two) GUI programs, the free community edition of Visual-Studio or any C or C++ compiler that can generate a Windows program with WinMain() would suffice.

To implement that you need to have the base program which performs an encryption your exe with the given password and create primary executable - let's call this application "Creator". In this application you specify the password and select an exe file to create the resulted exe. Another program which we call "Host" will be executed at start instead of encrypted program, it just popup the window for the entering password and use that password to decrypt the primary executable and then start it as the new process. The encrypted data can be stored as extra data as the tail of the Host application, as this application has always the same size it knows the start reading position of itself from the disk. The host application can be stored in the Creator resources and used from there to create protected executable - just read it from there write to the resulted file and then append the encrypted tail.
That is the basic implementation it is possible to have many extra things to make it more complex, but what I mention is enough to start coding :)

Regards,
Maxim