You can execute Python code in a virtualenv from Matlab by calling the Python executable from within the virtualenv using the system command in Matlab.

Here are the steps to follow:

1. Activate the virtualenv in the terminal by running the activate command (e.g., source /path/to/virtualenv/bin/activate)

2. In Matlab, use the system command to call the Python executable within the virtualenv. For example, if your Python script is named myscript.py and is located in the virtualenv directory, you can run the following command: 

system('/path/to/virtualenv/bin/python /path/to/virtualenv/myscript.py')

This will execute the myscript.py file within the virtualenv, using the Python interpreter located in the virtualenv's bin directory.

Note: Replace /path/to/virtualenv with the actual path to your virtualenv directory.