If you have a secondary cell value that you want to count, the examples shown below are very easy to modify.
=COUNTA('Walk In'!A2:A500)-COUNTIF('Walk In'!A2:A500,"VBA")
The above formula will return the number of all entries in the examined range which are not "VBA".
If there is no space in the work sheet's name you can omit the apostrophe.
=COUNTA(IT!B2:B500)-COUNTIF(IT!B2:B500,"VBA")