How to pass string using SendMessage

Hi all,
In my SDI application,i am trying send a custom message from dialog box to CScrollView.Along with that message i need to pass a string Value.I know how to send the String using SendMessage.But how to retrieve the string in the destination function,Bcos the parameter LPARAM is of LONG_PTR.How can i convert this into string,Here is my code..

CString DelVar;
SendMessage(WM_MYCHANGEVARIABLE,NULL,(LPARAM)&DelVar);

In the Destination,
LRESULT CTestView::OnMyChangeVariable(WPARAM,LPARAM)
Now My string is in LPARAM,How could i access it,Can any Pls help on this,

Shiva..

Just cast the LPARAM pointer back to a CString pointer when you get that message.