How To Write One Sql Statement Into Another

I am new to using sql statement in my codes. I need help in writing a sql statement using one sql statement (sql_1) in another (sql_2)? In the sql statements below, I am trying to replace "query2" with the sql statement (sql 1). Please help

sql 1: SELECT tbl_HourTypeMaping.CustomerCode_HTMP, tbl_HourTypeMaping.HourTypeCode
FROM tbl_HourTypeMaping
WHERE (((tbl_HourTypeMaping.CustomerCode_HTMP)="htmp_default"));

sql 2: INSERT INTO tbl_HourTypeMaping ( CustomerCode_HTMP, HourTypeCode )
SELECT Query2.CustomerCode_HTMP, tbl_HourType.HourTypeCode
FROM tbl_HourType LEFT JOIN Query2 ON tbl_HourType.HourTypeCode = Query2.HourTypeCode
WHERE (((Query2.CustomerCode_HTMP) Is Null));