Cache has different mechanisms for calling in from the OS to start Cache functionality. See http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=....
Several other possibilities I've used:
1) Your BAT file creates a "trigger" file (for example: MyTrigger.txt) when you want to do a backup. A Cache routine checks for the existence of the trigger file every five minutes and when the Cache routine notices the file, it deletes the trigger file and does ^DBACK.
2) Your BAT file stops Cache by doing cstop.exe in Intersystem/Cache/bin, then you OS copy the Cache.dat file (Cache namespace/database file), then does cstart.exe. Note: Cache will be DOWN while the copy is being made. You can dirty copy Cache.dat while Cache is running but there's no guarantee your copy DB will not be corrupt.
Tom Fitzgibbon | gototomAtG...l.com | 917-933-1226