This function returns whether a check box in a table cell is checked.
SapGui.bdh
SapGuiTableIsCheckboxChecked( in sControlId : string; 
                              in nRow       : number;
                              in nCol       : number ) : boolean; 
               	 | Parameter | Description | 
|---|---|
| sControlId | The unique id of the control. | 
| nRow | The cell's row. | 
| nCol | The cell's column. | 
transaction TMain
  var
    bCheck : boolean;
    sConnID : string;
  begin
    // Connecting to SAP
    sConnID := SapGuiOpenConnection( " /SAP_CODEPAGE=1100 /FULLMENU 10.5.2.132 0 /3");
    SapGuiSetActiveConnection(sConnID);
    SapGuiSetActiveSession("ses[0]");
    // SAP
    SapGuiSetActiveWindow("wnd[0]", "SAP", SAPGUI_MATCH_ExactNoCase);
    SapGuiWindowAction(SAPGUI_WND_MAXIMIZE);
    SapGuiLogon("ddic", "*******", "000", "");
    bCheck := SapGuiTableIsCheckboxChecked("/usr/tab/table23", 0, 0 );
  end TMain;