The query below will get you the number of test steps created in Test Plan. You will need to tweak it some to fit your needs. 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 - For testing purposes, I used the Test_Folder_Parent - AAAAAA, and Test_Folder_Child - AAAAAAAAA as you will see in the queries below.
SELECT COUNT(DS_ID) As 'Test Step Count in Test Plan'
FROM DESSTEPS, CYCLE, CYCL_FOLD, TESTCYCL
WHERE CF_ITEM_PATH IN ('AAAAAA', 'AAAAAAAAA')
AND CF_ITEM_ID = CY_FOLDER_ID
AND TC_CYCLE_ID = CY_CYCLE_ID
AND TC_TEST_ID = DS_TEST_ID