I understood your plan but I don't know if it will work. Below is the SQL for the original query (qryNewFte) that calculates the New ratio. I guess the only field you're interested in this code is the field "NewFte".
SELECT CCADMIN_CC_EMPLOYEE.CSR_AGENT_NO, tblAdpPayroll.FileNumber, tblAdpPayroll.HoursWorked, tblAdpPayroll.Overtime, tblAdpPayroll.VacationHours, IIf([EMPLOY_TYPE_CD]=1 Or [EMPLOY_TYPE_CD]=3,[HoursWorked]+[Overtime]+[VacationHours],[HoursWorked]+[Overtime]) AS TotalHours, CDbl(Format([TotalHours]/80,"#.0"

) AS NewFte, CCADMIN_CC_EMPLOYEE.EMPLOY_TYPE_CD
FROM CCADMIN_CC_EMPLOYEE INNER JOIN tblAdpPayroll ON CCADMIN_CC_EMPLOYEE.MISC_TEXT_1 = tblAdpPayroll.FileNumber
WHERE (((CCADMIN_CC_EMPLOYEE.EMPLOY_END_REASON_CD) Is Null));
Another SQL code of the Append query I created (except for the ID field that we are trying to solve):
INSERT INTO CCADMIN_WORK_HISTORY ( CSR_AGENT_NO, JOB_FUNCTION_CREATE_DATE, CC_TEAM_MANAGER_ID, LOCATION_CD, CSR_MERIDIAN_ID, SALES_REP_NO, CSR_STATUS_CD, TEMP_ASSIGN_ID, EMPLOYER_CD, EMPLOY_TYPE_CD, JOB_FUNCTION_CD, CC_GROUP_CD, POSITION_EFFECTIVE_DATE, LAST_UPD_DATE, LAST_UPD_USERID, JOB_FUNCTION_CREATE_USERID, OPER_ID, FTE_RATE )
SELECT CCADMIN_CC_EMPLOYEE.CSR_AGENT_NO, Date() AS JOB_FUNCTION_CREATE_DATE, CCADMIN_CC_EMPLOYEE.CC_TEAM_MANAGER_ID, CCADMIN_CC_EMPLOYEE.LOCATION_CD, CCADMIN_CC_EMPLOYEE.CSR_MERIDIAN_ID, CCADMIN_CC_EMPLOYEE.SALES_REP_NO, CCADMIN_CC_EMPLOYEE.CSR_STATUS_CD, CCADMIN_CC_EMPLOYEE.TEMP_ASSIGN_ID, CCADMIN_CC_EMPLOYEE.EMPLOYER_CD, CCADMIN_CC_EMPLOYEE.EMPLOY_TYPE_CD, CCADMIN_CC_EMPLOYEE.JOB_FUNCTION_CD, CCADMIN_CC_EMPLOYEE.CC_GROUP_CD, Date() AS POSITION_EFFECTIVE_DATE, Date() AS LAST_UPD_DATE, CCADMIN_CC_EMPLOYEE.LAST_UPD_USERID, CCADMIN_CC_EMPLOYEE.JOB_FUNCTION_CREATE_USERID, CCADMIN_CC_EMPLOYEE.OPER_ID, qryNewFte.NewFte
FROM CCADMIN_CC_EMPLOYEE INNER JOIN qryNewFte ON CCADMIN_CC_EMPLOYEE.CSR_AGENT_NO = qryNewFte.CSR_AGENT_NO
WHERE (((qryNewFte.NewFte)<>[CCADMIN_CC_EMPLOYEE].[FTE_RATE]) AND ((CCADMIN_CC_EMPLOYEE.EMPLOY_END_DATE) Is Null) AND ((CCADMIN_CC_EMPLOYEE.EMPLOY_END_REASON_CD) Is Null));
Thanks again for your help.
Note: I created a query selecting the Max record from Work History table and added it to the field +1, but obviously it appended the query with the same ID for all the records!