Are just the values of the attribute names dynamic? If so, I'm relatively certain you can do this with Mendix. You should be able to import the XSD and map them just like you would map a child element in XML. As an example, I took the XSD from the accepted answer of this StackOverflow question:
https://stackoverflow.com/questions/9946647/xsd-element-with-both-attributes-and-child-elements
<?xml version="1.0" encoding="utf-8"?>
<!--W3C Schema generated by QTAssistant/W3C Schema Refactoring Module (http://www.paschidev.com)-->
<xsd:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:element name="component">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="operation">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="input">
<xsd:complexType>
<xsd:attribute name="type" type="xsd:string" use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
<xsd:attribute name="name" type="xsd:string" use="required" />
</xsd:complexType>
</xsd:element>
<xsd:element name="event">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="output">
<xsd:complexType>
<xsd:attribute name="type" type="xsd:string" use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
<xsd:attribute name="name" type="xsd:string" use="required" />
</xsd:complexType>
</xsd:element>
</xsd:sequence>
<xsd:attribute name="type" type="xsd:string" use="required" />
<xsd:attribute name="binding" type="xsd:string" use="required" />
</xsd:complexType>
</xsd:element>
</xsd:schema>
and was able to import this XSD into the modeler and build an export mapping on it: