I put the TStaticText in a Panel. I fixed the size of the panel, but I set the size of the TStaticText to auto. Then I aligned right what I should, so now only the rightmost part of the TStaticText is visible.
Somehow I don't feel like using an extra var, but on the other hand, maybe I'll use your solution, since now the text is aligned right, even if it is not longer that the TStaticText.