I'm using Adobe Acrobat Pro XI and need to place a dynamic stamp
on every page of a pdf document. Of course I don't want to place that stamp
my problem, however I couldn't find that function in my version.
Unfortunately this is not possible (out of the box) with Acrobat. Using the Preflight tool you could create a fixup to stamp across multiple pages but it only works with the standard stamps and not dynamic ones.