Dynamically Using Sheetname in Sql-VBA

rs.Open "SELECT [Sheet1$].ID FROM [Sheet1$] WHERE [Sheet1$].ID IS NULL ", cn, adOpenKeyset, adLockReadOnly

Sheet1, i.e. the name of the sheet in my case is variable in my case and I want to repeat this query for 100 sheets, so how do I dynamically specify the name?

Thanks in advance.