Position window automaticly in TWM

The [man pages](http://www.x.org/archive/X11R6.8.2/doc/twm.1.html) of TWM tells me that if I specify a -geometry [size x size] + offset + offset, TWM will honor this and create the window in that location. For which types of windows is this possible? It is possible to set a geometry for xclock and xterm, but not for gvim. How can I initially position gvim - for example - at a given position on my screen?