Your batchfile might look like this:
@echo off
cdcd backup
if exist myfile.10 then del *.10
if exist myfile.9 then ren *.9 *.10
if exist myfile.8 then ren *.8 *.9
...
...
if exist myfile.pst then ren *.pst *.1
cdcd mypath
xcopy32 /k/r/y/c/h/e/f *.pst c:\backup
This will make a stack of ten copies of your data, allowing time to recover from accidental corruption. You can also copy across a network, provided that you call the batchfile in protected mode only.
Example:
XCopy32 /k/r/y/c/h/e/f *.pst \\computer\shared\backup