How do I use 64-bit tools in tcl script under Windows?

Don't you hate it when you ask what you suspect is probably a stupid question but you ask it anyway and then the answer comes to you 15 minutes later?

I run the tcl script from the DOS command prompt using a command like "quartus_sh -t build_all.tcl". (where "build_all.tcl" is my tcl script) Prior to doing that, I set the PATH environment variable to include the location of the quartus_sh executable. For instance, on my system, I add "C:\altera\12.0\quartus\bin" to the beginning of the PATH variable. If I instead add "C:\altera\12.0\quartus\bin64", it runs the 64-bit shell, and it invokes the 64-bit tools.

I imagine one could also just invoke quartus_sh using it's full path name but have not tried that.

Hopefully someone finds this useful.