wix - fill edit-control with value from registry

Question

Installer is writting SQL Server's name to registry during installing my service. And I created a dialog window with edit control where user will type the servername . Now I want to fill this control with value from registry in ChangeMode. And if this registry key is empty to fill with some default name. How is possible to resolve it? I tried to put RegistrySearch node into Control node. But it seems to me it's not working.. Any help is appreciated

P.S. Looked some information here: link1. And tried code like:

<Property Id="SERVCONNSTR" Value=".\SQLEXPRESS">            
        </Property>
<Property Id="CONNSEARCH">
<RegistrySearch Id="servconstr" Root="HKLM"
    Key="Software\$(var.Manufacturer)\SERVICE" Name="SQL Server" Type="raw"></RegistrySearch>
</Property>
<SetProperty Id="SERVCONNSTR" Value="CONNSEARCH"
     After="AppSearch"><![CDATA[CONNSEARCH AND (!FEATURE1=3 OR !FEATURE2=3 OR !FEATURE3=3)]]></SetProperty>

But I'm still getting .\SQLEXPRESS in edit-control during modifying.

What i'm doing wrong?

Answer 1

<Property Id="SERVCONNSTR" Value=".\SQLEXPRESS">            
        </Property>
<Property Id="CONNSEARCH">
<RegistrySearch Id="servconstr" Root="HKLM"
    Key="Software\$(var.Manufacturer)\SERVICE" Name="SQL Server" Type="raw"></RegistrySearch>
</Property>
<SetProperty Id="SERVCONNSTR" Value="[CONNSEARCH]"
     After="AppSearch">CONNSEARCH</SetProperty>