How to set environment variables with bat file before starting python debugging in vscode

I'm doing simulations with Adams Car 2020 and Python. I use the internal Adams Python functionality. In this internal python environment I don't have matplotlib available for example. Therefore I've created a virtual python environment which has extra packages which I start from Adams Car Python as a subprocess.

Before we start Adams Car we set some of the environment variables with a Batch file, let's say set_env.bat. I need these environment variables as well when I start python in the virtual environment. I can do this with a batch file where I first call set_env.bat and then call the virtual env Python:

start_ext_python.bat:

call set_env.bat
call <path_to_python_virtual_env> %1

where the first argument is the path to the python script I want to execute.

I would like to use Vscode debugging and call set_env.bat. Therefore I made a task which I refer to in launch.json:

tasks.json:

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "label": "init_acar",
            "type": "shell",
            "command": "C:\\User\\lj012145\\Git\\Adams\\source_a2cm\\bat\\ADAMS_Set_Environment.bat"
        }
    ]
}

launch.json:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: Test adams external file",
            "type": "python",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal",
            "cwd": "${workspaceFolder}",
            "preLaunchTask": "init_acar",
            "args": [],
        },

    ]
}

This runs the bat file first but the environment variables are not set anymore when I stop the debugger in my python script.

I could also create a set_env_vscode.bat which writes to a .env file which I refer to then but I'm not sure if that is a good approach..