image duration

two part question.
1. If I use (d5); I get a 5 second image duration. So if I use (d5.123); do I get a 5123 msec duration?

2. Can I randomize duration? For example, can I ask for 5 seconds, on average, but range between 1 sec and 10 sec - and have the system randomly insert a duration within that range?

DirectRT can do both of these but MediaLab can't--do you have access to DirectRT? MediaLab uses an integer second timer for the duration parameter.