1. Create a file called Extension-Registry.xml, add to your project and add this xml:
<ExtensionObjects>
<ExtensionObject Namespace="http://schemas.microsoft.com/BizTalk/2003/Registry" AssemblyName="mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" ClassName="Microsoft.Win32.Registry" />
</ExtensionObjects>
2. Open your map file, select the grid and set the Custom Extension Xml property to the file above
3. Add this namespace to the <xsl:stylesheet> node of your custom Xslt
xmlns:Registry="http://schemas.microsoft.com/BizTalk/2003/Registry"
4. Add this xslt code where appropriate:
<xsl:element name="Value">
<xsl:value-of select="Registry:GetValue(<keyName>, <valueName>, <defaultValue>)" />
</xsl:element>