Freeze anim is a 3ds Max script from Chuggnut that seals stack-based animation into vertex-based animation. In keeping with its name, it converts animation held on the stack into a vertex-based form.
There is one important limitation worth flagging: Freeze anim does not save space warp links. When the animation is sealed into its vertex-based form, existing space warp links are not carried over, so if your scene relies on those links you'll want to plan around this behaviour before running the tool.
This listing covers version 2.3.5, available through ScriptSpot with a link to Chuggnut's own website. For the download, current licensing details and any additional usage notes, the developer's page is the place to check before adding it to your 3ds Max toolset.