Use complex type many places

Hello,
I have a simple XML file:
<?xml version="1.0" standalone="yes"?>
<mytext xml:space="preserve">the text</mytext>

I have a complex type that manages the xml:space attribute. The xsd
looks like this:
<?xml version="1.0"?>
<xs:schema attributeFormDefault="unqualified"
elementFormDefault="qualified"
xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:import namespace="http://www.w3.org/XML/1998/namespace" 
schemaLocation="xml.xsd"/>
<xs:element name="mytext">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute ref="xml:space"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
</xs:schema>

Everything works fine.

Now I want to add a new line to my XML so it looks like this:
<?xml version="1.0" standalone="yes"?>
<mytext xml:space="preserve">some text</mytext>
<mynumber xml:space="preserve">5555</mynumber>

I know that complex types can be named and reused, but I have not been
able to figure out the correct syntax. I am hoping not to repeat the
complex type under each element in my xsd ( because any element could
have the xml:space attribute ).
When I put the complex type under the <mynumber> element in the xsd, it
breaks because the <mynumber> element is of type decimal.

How can I reuse the complex type?
How do I use the complex type in the mynumber element and still maintain
the business rule saying that the mynumber tag should always contain
decimals?

Any help is greatly appreciated.
Thank you.
Shannon