It should work fine.
The ScummVM executable is a 32-bit installer and works fine on 64-bit Windows.
It's 16-bit exe's that are the problem with 64-bit Windows.
Download ScummVM from
http://scummvm.org/downloads/To install a game in ScummVM, you first copy the required files and/or folders from the game to a folder on your hard drive. The files/folders will be different for different games. The ones you need for Toltecs are listed here:
http://wiki.scummvm.org/index.php/Datafiles#3_Skulls_of_the_Toltecs SAMPLE.AD
SAMPLE.OPL
WESTERN
Then start ScummVM, click the "Add Game" button, and browse to the folder where you put the Toltecs files. If you've got the right files, Scumm should detect them.
It's really pretty easy -- easier than configuring DOSBox anyway.