You can set a data breakpoint, that can trigger when an operation occurs on data at a certain address in memory. To add a data breakpoint the program already needs to have started running - ideally it would be paused at a normal breakpoint ahead of where you expect the clobbering, but after the point where the storage for the relevant array has been created. At this point you can use Debug > New Breakpoint > Data breakpoint, For the address you may use a fortran-like expression, such as `LOC(array(5))` - i.e. the memory location of the fifth element of the variable named array.
(Details may vary slightly depending on Visual Studio version.)