check if file exists on remote system ?

Hi there, I am designing a software rollout script and need to check if a particular file exists on a remote system

something along the lines of

if [ -f `ssh remote_box /opt/SUNWexplo/bin/explorer` ] ; then blah blah

The above doesnt work but you get the general idea....is there a way I can do this on a single line ??

any help would be greatly appreciated

if [ -n "`ssh $REMOTE 'ls /opt/SUNWexplo/bin/explorer'`" ]; then blah; blah; blah; fi 2>/dev/null

Carl

perfect thank you