BurnInTest provides the capability to script a series of tests. With BurnInTest scripting you can display messages to prompt a user to take some action, like close the lid of the laptop. So, you could script a test to: Run test part 1, Display message to close/re-open lid then Run test part 2.
The script (in its simplest form) would be something like:
RUN config
MESSAGE "Close the laptop lid and re-open it, then press OK to re-start the test."
RUN config
Please see the User Guide for the many scripting options (section 10.3):
http://passmark.com/ftp/BIT_Users_Guide_Ed7_0.pdf
Another option to force a sleep state is using our "Sleeper" software to force the sytem into one of its supported sleep states. Again you can do this from a BurnInTest test script, using the EXECUTEWAIT sleeper command (See EXECUTEWAIT in section 10.3 of the user guide).
You can try all of this with the evaluation software from here:
http://passmark.com/download/bit_download.htm