Thanks Mike, I might try that but I have a working solution... although it feels a bit hacky

    // I get the tabID for the selected page in my UrlControl control (ddlPageLinks), then search the TabInfo object for that item
    int tabId = Convert.ToInt32(ddlPageLinks.Url);
    var redirectTabInfo = TabController.GetPortalTabs(PortalId, this.TabId, true, false)
            .Where(t => t.KeyID == tabId)
            .Single();

    // then update the Settings with that KeyID, and the FullUrl
    modules.UpdateTabModuleSetting(this.TabModuleId, "DateRangeHyperLinkUrl", redirectTabInfo.FullUrl);
    modules.UpdateTabModuleSetting(this.TabModuleId, "DateRangeTabId", redirectTabInfo.KeyID.ToString());

Then when loading the View.ascx I have the Url to the selected page, and when loading the Settings.ascx control I have the TabId (for the UrlControl's "SelectedValue" property - actually called "Url")

Thanks again Mike. The requirements just changed, so now I have another question: what if the user uploads a file? Then the Url property of the UrlControl is something like 

FileID=12345

Which I wouldn't want to cast as an int. All I can think to do is
 - Strip out the "FileID=" portion
 - Store this as my "LinkUrl" or something in Settings
 - Store UrlType in my Settings
 - Use a switch statement on UrlType to determine what I'm going to do with the Id stored in LinkUrl

There must be an easier way.

Hello,

With files, it's usually easiest to get them out of the LinkClick function. This returns a protected URL that can also handle logging (if setup/applicable).

DotNetNuke.Common.Globals.LinkClick("FileID=4") will give the url for that fileID.

Hope this helps,

Mike