bitcoind confirmations

[sudocoin]

How does one go about checking the number of confirmations for a given transaction id? One that is external to the local wallet.dat file. Can this be done with bitcoind or will I have to use an API or something else?

Is this correct for a given txid?

block-included = 295503
block-now = 295504

confirmations = block-now - block-included = 295504 - 295503 = 1