How to create/edit excel by office open xml standard

Question

What I have searched & read:

• C# .xml to .xlsx how? - Stack Overflow
• .net - How do I create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office? - Stack Overflow

What I have tried:

I have tried to parse the xml to a DataTable and then create/edit excel using EPPlus. But the excel xml format depends on the API.

What I expect:

e.g.: if there is a xml text like:

<excel>
    <name>demo</name>
    <Workbook>
        <sheet name='sheet1'>
            <Row>
                <Cell>ID</Cell>
                <Cell>Name</Cell>
            </Row>
            <Row>
                <Cell>1</Cell>
                <Cell>Wei</Cell>
            </Row>          
        </Sheet>
        <sheet name='sheet2'>
            ...
        </Sheet>        
    </Workbook>
</excel>

I expect some method to parse xmlText to excel

var xmlText = @"<excel>...</excel>";
var excel = SomeExcelTool.Parse(xmlText);

If such a method exists, where can I search the standard xml format for excel?