how-do-i-set-up-a-url-redirect-for-a-domain documents NameCheaps redirecting rules: It is important to note that the value in the

www.namecheap.com/support/knowledgebase/article.aspx/385/2237/how-do-i-set-up-a-url-redirect-for-a-domain documents NameCheaps redirecting rules:

It is important to note that the value in the Destination URL affects where and how the URL is redirected.

Host: www1.example.net
Destination: example.com
Host: www2.example.net
Destination: example.com/
In the first case, www1.example.net will not pass values to the destination URL, so www1.example.com/xyz.html will redirect users to example.com only. Thus, all values that you put in the original URL under your domain name will be left out.

In the second case, www2.example.net/xyz.html will redirect users to example.com/xyz.html (pay attention to the symbol "/" in the configuration). All values that are put into the original URL under the domain name will be included in the destination address and applied in the results.

You have to add the trailing slash on the destination URL to get NameCheap to preserve URL paths.