Please help in code

i have altered a code seen here, to track particular stock item billed in invoice. i couldn't get total of field fldmyqty, tried lots of parts where it may refer but couldn't got correct. please help me out!

Code -

[#Line: EI ColumnOne]
Add:Right Field:At Beginning:fldmyqty
Local:Field:fldmyqty:Info:$$LocaleString:"My Particular Item"
Local:Field:fldmyqty:Invisible:NOT @@ISpurchase
[#Line: cI InvInfo]
Add:Right Field:At Beginning:fldmyqty
Local:Field:fldmyqty:info:if $stockitemname contains "XYZ" then $billedqty else 0
Local:Field:fldtwqty:Invisible:NOT @@ISpurchase
Local:Field:fldtwqty:Read Only:Yes
Local:Field:fldtwqty:Set Always:Yes
[field:fldtwqty]
use:Qty Primary Field
format:"no symbol"
align:left

i need $$total:fldmyqty

 

Compute it in collection
or
Define it on Part Level
Total :YourField Name

 

Thanks for responce
i don't know how to use collection for a field (never seen before)
and for part level i tried all parts where these 2 lines called even their parent parts but no success

 

Dear
To get total of any field You need to define in part definition as Total:YourFieldName
[#Part: CI InvInfo]
Add : Total : fldmyqty

now you will get Total.

 

Thanks for help
I actually found that a couple of days before with reverse searching in tally developer, but couldn't posted here due to connectivity issue
thanks anyway