The query below will get you the tests that haven't been executed in Test Lab. You will need to tweak it some to fit your needs. I have entered the query, along with some additional info needed to prepare the query to run. First, you will need to access Site Admin, locate and expand the project you are wanting to gather the info from and select the 'CYCL_FOLD' table. Record the value(s) in the CF_ITEM_PATH column for the parent or child folder you are wanting to pull the tests from. For testing purposes, I used the Test_Folder_Parent - AAAAAA, and Test_Folder_Child - AAAAAAAAA as you will see in the query below.
The report will display the following fields - Folder ID, Folder Name, Test ID, Test Name, and Testers Name.

SELECT CF_ITEM_ID As 'Folder ID', CF_ITEM_NAME As 'Folder Name', TS_TEST_ID As 'Test ID', TS_NAME As 'Test Name', TS_RESPONSIBLE As 'Testers Name'
FROM TEST, CYCLE, CYCL_FOLD, TESTCYCL
WHERE CF_ITEM_PATH IN ('AAAAAA', 'AAAAAAAAA')
AND TS_EXEC_STATUS = 'No Run'
AND CF_ITEM_ID = CY_FOLDER_ID
AND TC_CYCLE_ID = CY_CYCLE_ID
AND TC_TEST_ID = TS_TEST_ID
GROUP BY TS_TEST_ID, TS_NAME, TS_STEPS, TS_RESPONSIBLE, TS_EXEC_STATUS, CF_ITEM_ID, CF_ITEM_NAME, CF_ITEM_PATH