To redirect an existing landing page to a new (existing) landing page, use the process below.
To update an existing Marketo landing page URL, reference this tutorial. Do not manually redirect via the process below.
Step 1: Click on Admin.
Step 2: Click on Landing Pages > Rules Tab. Select New > New Redirect Rule.
Step 3: Choose your CNAME from the drop-down menu (pages.elixiter.com) then choose the Marketo landing page you would like to redirect (Test.Test Page).
Step 4: If you would like to redirect to another Marketo landing page, select it from the Redirect URL drop-down menu (Testing.Test). Click Create and test the landing page. If you would like to redirect to a non-Marketo Landing page, move to Step 5.
Step 5: Click on Use non-Marketo Landing Page and enter-in your full destination URL.
Click Create and test the landing page.
Source: Marketo Community