[xsl] XPath expression to get the string following the open quote of an attribute?

["Roger L Costello costello@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hi Folks,

Here are sample input strings:

="abc"
= "abc"
=       "abc"

That is, an equals, zero or more whitespaces, quote, value, quote

I want everything after the first quote.

What XPath expression yields the desired result?

For all of the above inputs, the result of the XPath should be: abc"

/Roger