[ Caution: if you write your post and then click the disclaimer, you lose what you wrote. Yipes.]
What you're describing is called a niente attack. @Bastiaan has the only answer I know, but you indicate that you don't want to use Expression. I too have sought that sound using VelXF alone, and I don't think it can be done. Even at its lowest setting, the beginning of the sound is heard.
Other than a sampled niente attack, you cannot get the truest real-world sound anyway (and if somewhere in VSL's compendious library they've got it, so much the better.)
Unimaginatively, if CC 22 has a slow enough attack and you fiddle with track volume, you get a version of the sound without CC 11 Expression.
Oddly, a sampled diminuendo to niente may be as or more useful. But such sounds are better revealed in solo and chamber work. I don't think, for example, we need Appassionata niente attacks or releases.
You know, my spell checker really hates the word niente.