OleVariant as project variable

I know Project Variables have been covered many many times but I did not find an answer to this:

This code works fine, but I don't want to have to declare winMake in every procedure that accesses the application.

(DelphiScript)

procedure StartBtn_OnClick(Sender);
  var winMakeApp : OleVariant;
begin
  TestedApps.WinMake.Run(1, true);            (WinMake.exe is the name of the app I am testing)
  winMakeApp := Aliases.WinMake;

  ...
  do stuff with winMakeApp

But when I try to create a ProjectSuite variable, OleVariant is not a supported type.
How do I declare this?

Thanks