How can I find out to which filepath (or alias) a certain command input will point to, in the Windows command prompt? Specifically Windows XP, info on other versions also appreciated!

On Unix systems I simply use:

$ which commandname
/a/commandname

Or:

$ type -a commandname
commandname is aliased to `/b/commandname'
commandname is /a/commandname
commandname is /b/commandname

And I am simply looking for the equivalent in the Windows Shell (specifically Win XP).

I came to this general question, from a specific issue: I had installed robocopy.exe (version 026), but the command line "robocopy" always triggers version 010, and I would like to determine where this command points to, in order to correct this mistake.