Call a custom action after the install dialog is displayed but before a custom dialog is displayed

Hi,

I want to use a wix custome action to perform some operations based on the install directory selected by the user but before my custom dialog is displayed (the ConfigurationDlg dialog). This is part of the wix configuration:

<CustomAction Id="InitializeSettings" Return="check" Execute="immediate" Impersonate="no" BinaryKey="GatewayServiceCustomAction.CA.dll" DllEntry="InitializeSettings" />

<UI>

<UIRef Id="WixUI_InstallDir"/>

<DialogRef Id="ConfigurationDlg" />

<Publish Dialog="ConfigurationDlg" Control="Back" Event="NewDialog" Value="InstallDirDlg">1</Publish>

<Publish Dialog="ConfigurationDlg" Control="Next" Event="NewDialog" Value="VerifyReadyDlg">1</Publish>

<Publish Dialog="InstallDirDlg" Control="Next" Event="DoAction" Value="InitializeSettings" Order="2"></Publish>

<Publish Dialog="InstallDirDlg" Control="Next" Event="NewDialog" Value="ConfigurationDlg" Order="4">NOT Installed AND WIXUI_DONTVALIDATEPATH OR WIXUI_INSTALLDIR_VALID="1"</Publish>

<Publish Dialog="VerifyReadyDlg" Control="Back" Event="NewDialog" Value="ConfigurationDlg" Order="1">NOT Installed</Publish>

</UI>

<InstallUISequence>

<Custom Action="InitializeSettings" After="LaunchConditions"/>

</InstallUISequence>

Currently the InitializeSettings custom action is called too early i.e. before the install directory has been set in the UI.

How can I get the InitializeSettings custom action to be called after the install directory has been set but before the custom dialog is displayed?

Thanks

Ian