What is the algorithm for obtaining the attribute value through >own algorithm< in the exchange module 1C UT - Bitrix?

Question

1C-Bitrix

Exchange module 1C Bitrix with the site,
Section - Exchange of Orders
Setting the correspondence of uploaded documents - data type = <your algorithm>

please tell me the algorithm so that you can get the value of the Shipment attribute from the XML document

<Container>
<Document>
<Id>3Id>
<Number >N401Number>
<Date>2021-02-03Date>
<MasterOperation>Order GoodsMasterOperation>
<Role>
SellerRole> <Currency>rubCurrency>
<Rate>1Rate>
<Amount>455.0000Amount>
<VersionNumber>15VersionNumber>
<Accounts>... Counterparties>
<Time>13:26:50Time>
<Comment/>
<Taxes>...Taxes>
<Goods>...Goods>
<Attribute Values>
<Attribute Value>
<Description>ShippingDescription>
<Value>02/05/2021 00:00:00Value> Attribute
Value>

Answer 1

if anyone needs it, the solution is:
[Result] = GetDocumentAttributeValue([XML Document].AttributeValues, "Shipment");
A string will return.
If the attribute is in 1C of the Date type, then you need
Date( GetDocumentAttributeValue([XML Document].AttributeValues, "Shipment"));