Bex Query - How to get employees who do NOT have a Qualification

I have created two (2) queries, as follows:

Query 1
0EMPLOYEE - CUSTOMER EXIT - NOT READY FOR INPUT - HAS ABAP

0QUALIFICTN - CUSTOMER EXIT - NO ABAP

Query 2

0EMPLOYEE - Replacement path from Query1

Example

Execute Query2 (which executes Query1).  Select Qualification 'A' - the ABAP correctly selects and returns

all employees who do NOT have Qualification 'A'.

However, because the value entered into the variable for Qualificaiton in Query1 does not get cleared, the

result set is all employee who have qualificaiton 'A'.  This is the exact opposite of what we want.

So, how do I reset/clear the value entered for 0QUALIFICTN (e.g - 'A') within the ABAP of the 0EMPLOYEE Customer Exit,

or, how else can I accomplish this - e.g.- give me all employees who do NOT have Qualification 'A'.

Assistance appreciated.

Thanks.

Gerry