using ZapfDingbats font in DITA file

[IF]

How do I tell XMetal to use a specific font, for example ZapfDingbats, for two specific words inside a topic file?

Presumably, I need to create an xsl attribute set but I don't know how to specify the font - it seems that my only choices for font-family are sans, serif, and monospaced.

I'm using XMetaL Author Enterprise 6.0 SP1 with XMetaL Enhanced PDF output format.
 
I can see that the ZapfDingbats  font is listed in the fonts-mapping.xml file but I don't know how to specify it in my DITA topic file.

thanks
Isabelle

 <logical-font name="Serif">
                        <physical-font char-set="default">
                                <font-face>Times</font-face>
                        </physical-font>
                        <physical-font char-set="Simplified Chinese">
                                <font-face>AdobeSongStd-Light</font-face>
                        </physical-font>
                        <physical-font char-set="Japanese">
                                <font-face>KozMinProVI-Regular</font-face>
                        </physical-font>
                        <physical-font char-set="Korean">
                                <font-face>AdobeMyungjoStd-Medium</font-face>
                        </physical-font>
                        <physical-font char-set="Symbols">
                                <font-face>ZapfDingbats</font-face>
                        </physical-font>
                        <physical-font char-set="SubmenuSymbol">
                                <font-face>ZapfDingbats</font-face>
                        </physical-font>
                        <physical-font char-set="SymbolsSuperscript">
                                <font-face>Times</font-face>
                                <baseline-shift>20%</baseline-shift>
                                <override-size>smaller</override-size>
                        </physical-font>
                </logical-font>

[IF]

I am a bit closer thanks to  information gathered here: http://tech.groups.yahoo.com/group/dita-users/message/7717
For example, this is how I changed the symbol used for bullets

1.   I defined a logical font “Bullets” in C:\Users\\[username]\AppData\Roaming\SoftQuad\XMetaL Shared\DITA_OT\demo\xmfo\cfg\fo\font-mappings.xml
<logical-font name="Bullets">   
       <physical-font char-set="default">
                <font-face>ZapfDingbats</font-face>
        </physical-font>
</logical-font>

2.   I inserted a Unicode value for the bullet (a heavy checkmark in this case) in  C:\Users\[username]\AppData\Roaming\SoftQuad\XMetaL Shared\DITA_OT\demo\xmfo\Customization\common\vars\en_US.xml
<variable id="Unordered List bullet">&#x2714;</variable>   

3.   I modified the definition of the attribute set ul.li__label__content in  C:\Users\[username]\AppData\Roaming\SoftQuad\XMetaL Shared\DITA_OT\demo\xmfo\Customization\fo\xsl\custom.xsl
  <xsl:attribute-set name="ul.li__label__content">
<xsl:attribute name="font-family">Bullets</xsl:attribute>
    </xsl:attribute-set>