XSL & DTD question

<!DOCTYPE MYDOC SYSTEM "my.dtd" [

<!ENTITY % globals SYSTEM "globals.dtd">

%globals;

]>

<MYDOC>

</MYDOC>

and so on. 

But if I want to make the same set of constant entities available to an XSL file (still XML, right?), I run into a variety of problems, the first of which is that the first element of my XSL file is likely to be <xsl:stylesheet>.  This element does not agree with the document name 'MYDOC'. 

So, I reasoned, perhaps I can make the DOCTYPE statement refer to a public identifier for the DTD that defines the XSL vocabulary.  Alas, I can find no such public identifier.  More to the point, this seems like more work than should be necessary.

In fine, how would you handle this?  All I'm really trying to do is give my XSL files access to the set of shared constants that reside in globals.dtd.

Thanks in advance.

Cordially,

Paul