Use column value in M Query / Power Query - soap

Question

I've a short code to make a SOAP request to fetch data into Power BI. The problem is that I need to give a Session_id for the requests:
let
SourceURL = "HTTPS://SOAP.E-BOEKHOUDEN.NL/SOAP.ASMX?WSDL", //host provides this address. Url ends often with "wsdl"
options = [ #"Authorization" ="Basic USER:PASS=", //User:pass decoded with SOAP UI
#"Accept-Encoding"= "gzip,deflate",
// SOAPAction="",
#"Content-Type"="text/xml;charset=UTF-8",
#"Connection"="Keep-Alive"
],
WebContent = Web.Contents(SourceURL,
// Content options in Web.Contents() requires you to authenticate anonymously !
[Content=Text.ToBinary("
<soap:Envelope xmlns:soap=""http://www.w3.org/2003/05/soap-envelope"" xmlns:soap1=""http://www.e-boekhouden.nl/soap"">
<soap:Header/>
<soap:Body>
<soap1:OpenSession>
<!--Optional:-->
<soap1:Username>***</soap1:Username>
<!--Optional:-->
<soap1:SecurityCode1>***</soap1:SecurityCode1>
<!--Optional:-->
<soap1:SecurityCode2>***</soap1:SecurityCode2>
<!--Optional:-->
<soap1:Source></soap1:Source>
</soap1:OpenSession>
</soap:Body>
</soap:Envelope>
"),
Headers=options]) ,
XmlContent = Xml.Tables(WebContent)
in
XmlContent
Now this code is to get the Session_id. To get the other data I need to give the session_id instead of SecurityCode2 in a similar request:
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:soap="http://www.e-boekhouden.nl/soap">
<soapenv:Header/>
<soapenv:Body>
<soap:GetMutaties>
<!--Optional:-->
<soap:SessionID>***</soap:SessionID>
<!--Optional:-->
<soap:SecurityCode1>***</soap:SecurityCode1>
<!--Optional:-->
<soap:cFilter>
</soap:cFilter>
</soap:GetMutaties>
</soapenv:Body>
</soapenv:Envelope>
Can I use a column value as parameter/variable that I can use in the body?

Answer 1

You don't even need a column for that. Create a query that just returns a string:
and then you can reference that query anywhere else: