use of sql:column in XQUERY

Hi all
I tried forllowing XQuery and it's working fine
DECLARE
@Name nvarchar(100)SELECT
@Name = 'Calvin'DECLARE @xmldoc xmlSET @xmldoc = '<Root>
<Employee EmployeeID="1">
<EmployeeInformation>
<FirstName>Scott</FirstName>
</EmployeeInformation>
</Employee>
</Root>'SELECT
@xmldocSELECT
Employee.col.value('FirstName[1]','VARCHAR(100)') AS FirstNameFROM
@xmldoc.nodes('/Root/Employee/EmployeeInformation') Employee(col)SET @xmldoc.modify('replace value of (/Root/Employee/EmployeeInformation/FirstName/text())[1]
with sql:variable("@Name")'
)SELECT
@xmldoc
Now I wants to use sql:column() in staid of sql:veriable()
something like thisSET @xmldoc.modify('replace value of (/Root/Employee/EmployeeInformation/FirstName/text())[1]
with sql:column("pc.FirstName")'
)FROM
Person.Contact
WHERE ContactID =1SELECT
@xmldoc
This gives me error
Any help please
Thank You

Thanks satya for replay
So if I wants to update XML I need to have it to store it some SQL Table
Also is their any way i can Update multipal nodes of XML using in one commnd?
Thanks