how to register dll with ExeCommand='' with administrator privilege in wix?

<Fragment>
        <Binary Id="ProteusRegAction" SourceFile="..\ProteusRadioInstaller.CustomAction\bin\Release\ProteusRadioInstaller.CustomAction.CA.dll" />    <CustomAction Id="SaveRegistrationDataAction" BinaryKey="ProteusRegAction" DllEntry="SaveRegistrationData" Execute="immediate" Return="check" />
        <CustomAction Id="DeleteRegEntry" BinaryKey="ProteusRegAction" DllEntry="DeleteRegEntry" Execute="immediate" />
        <CustomAction Id="RegisterAxvlc" Directory="INSTALLLOCATION" ExeCommand='[SystemFolder]cmd.exe /C start regsvr32 "[INSTALLLOCATION]axvlc.dll"' Return="check" Impersonate="no"/>        
        <InstallExecuteSequence>
            <RemoveExistingProducts Before="InstallInitialize" />
            <Custom Action="DeleteRegEntry" Before="InstallValidate"> </Custom>
            <Custom Action="SaveRegistrationDataAction" After="InstallFinalize"><![CDATA[NOT Installed]]></Custom>
            <Custom Action="RegisterAxvlc" After="InstallFinalize">NOT Installed</Custom>

i am using this its working but its not give output correctly when i am run commond from start->cmd->(run as admin)-> C:\Windows\system32>regsvr32 "C:\Program Files\Myprojcet\axvlc.dll" its work nicely without any error.

so plz tell how this command run from wix installer?