[texhax] \vskip

[Chris Bourke]

> Skips are always relative to the current position.  You do not know
> where on the page you are.  The output routine might even decide that
> the position you insert the skip will move to the next page.

yes, but is there another command built in, or package or something?
Maybe I should explain; I'm trying to make a theme in the Beamer
Presentation package.  It has a sidebar tab that lists the sections and
subsections.  When it is done, the position is at the end of the last
section that it typeset.  I then need to jump back up to the top of the
sidebar.  If I use \vskip I would need to know how far down its typeset
all the sections/subsections, but this is not possible at the moment (the
package apparently doesn't support it, though it does keep lengths and
heights of all these elements).

The only way I could do it is if I were able to jump up to the top of the
page, THEN I would know how far back down to go.  \vskip clearly doesn't
do this, so is there another way?