You use the OPENXML command to get the XML into a tabular form. This is a very basic example but it shows the syntax.
DECLARE @xml AS XML
DECLARE @hDoc AS INT
SET @xml = '<root><data name="value" /></root>'
EXEC sp_xml_preparedocument @hDoc OUTPUT, @xml
FROM OPENXML (@hDoc, '//')
WITH (name NVARCHAR(10) '@name') AS a
EXEC sp_xml_removedocument @hDoc
If you have the XML data in an XML file you can use the BULK INSERT command to load the data into a temp table then get the value from the temp table and put it into a variable for processing by the OPENXML command. If you need an example of that let me know.