Editing UCDEF in certain records of ITEMASA file with Query/400

Hi Mapics Group:

I want to edit a the UCDEF field (it is a numeric field that is populated with 
values and it should be "zero" for certain Item Types in our system) in ITEMASA 
for certain Item No. records and I'm wondering if it can be done using 
Query/400?

For example:

Step # 1:  Use Query # 1 to copy the entire fields of the specific records into 
a new file called ALTEST1

Step # 2: Use Query # 2 to input ALTEST1 and use Define Result Fields to create 
a new substitue field (UCDEFCHG) with a numeric value of zero.  The output of 
this query goes to ALTEST2.

Step @ 3: Use Query # 3 to input ALTEST2 and use Define Result Fields to create 
the original field name, UCDEF, (which does not appear in ALTEST2) with a 
numeric value of zero.  Then, using Select and Sequence Field, I replace the 
UCDEFCHG field with the UCDEF field.  The output of this query goes to ALTEST3.

Now AlTEST3 has the records of the specific Item Nos. with a corrected UCDEF 
that now shows zero.

My problem is can I use Query/400 to replace the original records in ITEMASA 
with the records now contained in ALTEST3?

How do I do this?

I realize that there are other ways to accomplish this task (for example, using 
DBU or Mapics File Maintenance to edit UCDEF in the records in question; but 
the problem here is that there a way to many records involved in this matter to 
manually edit them).

Also, the reason we populate UCDEF with zero for Type 1 and Type 2 Item Nos. is 
that if they are populated with their correct Standard Cost, the screw up our 
cost estimating program that is used to quote product sales prices for 
customers.

In particular, the Bill of Material gets overstated: It would show Standard 
Costs for the detailed raw materials and purchased components that are part of 
the Inv Type 1 and 2 items along with their own UCDEF cost of the completed 
Type 1 and 2 Item.

As usual, I look forward to reading your fine suggestions.

Regards,
Al Gershen
Grants Pass, OR
aldg@mail.rvi.net