Passing variable through url and useing variable using macro

[#1]

Hello,
Lets say I have  a very simple app that has a text box only. an OnOpen Trigger defined on the document setting (WhenOpen). The trigger suppose to get the variable from url and show its value on the text box.

lets say the text box object ID is = TX13, I have defined the variable v and its default value is 0. The variable v is defined inside Text box text.

My url would be something like this :

http://localhost/QvAJAXZfc/opendoc.htm?document=Dynamicupdate%2Fdynamic_update_dix_5(1).qvw&host=QVS...

I have an incomplete macro code as well which is :

Sub WhenOpen

set v= ActiveDocument.GetVariable("val1")

End Sub

Please take note :

1- I know you can append variable to URL for customized select such as :

url&SELECT=THEOBJECTID,THEOBJECTVALUE

or you can change sheet using  :

URL&SHEET="SHEETID"

or even more advance customized url such as :

URL&object=OBJECTID

but none of these methods can not help me in this scenario.

2- this application suppose to open using access point on server.

Can you help me to complete the macro code to get the variable  from url and show its value on the text box please ? 

Many Thanks.

Cheers.