you can leverage the umbraco event handler framework... on create automatically populate the title param...

public class SetDefaultsHandler : ApplicationBase
    {
        public SetDefaultsHandler()
        {
            Document.New += new Document.NewEventHandler(Document_New);
        }

        void Document_New(Document sender, umbraco.cms.businesslogic.NewEventArgs e)
        {
            Document doc = (Document)sender;

            try
            {

                doc.getProperty("altTitle").Value = "SOME TEXT CONSTRUCT";
            }catch{}
        }
    }

Thanks a lot Mike, I am not really sure how to use your script :(

I figured out a bit different solution. I am planning to create a few macros with different descriptions or titles and then pull them by using one of the properties of my documents. I struggle a bit with it as I cannot directly pass value from property to macro. When I do:

<umbraco:Macro Alias="<umbraco:Item field="titleNumber" runat="server" />" runat="server"></umbraco:Macro>

 although in html I can see that value has been passed it do not actually pull the macro...

Any way to do that? 

With regards to using the above script... you need to build a class library in Visual Studio, generate the dll and simply place in your bin folder on your site.

with regards to your workaround... I think you probably need your macro to to ask for the titleNumber in the macro script and then you can use the inbuilt

umbraco.library:RenderMacroContent()

http://our.umbraco.org/wiki/reference/umbracolibrary/rendermacrocontent

Thanks a lot for your tips Mike! I realized how little I know and spent a few last days changing this :)

Got a bit distructed in the process but I am making a good headway and will try to sort this problem out soon. 

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