Here's one way. Not sure it's the best way and it doesn't use OPENXML though:

DECLARE @Books XML = '

<bookstore>

<book>

<title lang="eng">Harry Potter</title>

<price>29.99</price>

</book>

<book>

<title lang="fre">Learning XML</title>

<price>39.95</price>

</book>

</bookstore>'

SELECT title

,[language]=(

SELECT TOP 1 z.value('@lang[1]', 'VARCHAR(1000)')

FROM x.nodes('bookstore/book/title') c(z)

WHERE title = z.value('(.)[1]', 'VARCHAR(1000)')

)

,price=y.value('(price)[1]', 'MONEY')

FROM (SELECT @Books) a(x)

CROSS APPLY x.nodes('bookstore/book') b(y)

CROSS APPLY (SELECT title=y.value('(title)[1]', 'VARCHAR(1000)')) c

Note the TOP 1 on the correlated sub-query is there in case the same book title appears with multiple languages. In that case, the sub-query won't return the correct result but at least won't fail. To correct a case like that, you'd need to have something unique in the correlation like ISBN.

Edit: Added the second CROSS APPLY to clean it up a little.