You can do this way:
Suppose you have folder named as QV_QVD where all qvds are present . I'm considering you are having qvds names for example ABC_EINHEIT.qvd , XYZ_EINHEIT.qvd ...etc.
Now suppose you want to load a qvds for only ABC than use this script below:
Set vPlant = 'ABC';
Set vQVD = '\.......\QV_QVD';
FROM $(vQVD)\$(vPlant)_EINHEIT.qvd (qvd)