Making a dialog topmost

This is for a bunch of restaurant managers who we can't trust to give them system functions like task manager and task switching. They might accidently take down the server or stop a process like the credit card processing application. The system runs a managing menu application all the time. We have users launching a report application that has a pick list and when they go make their selection they are accidently clicking on the managing application and because they can't task switch, they can't get back to the report. Then they try to run the report again and it gives them errors bacause the application is already running. At that point the only thing they can do is logoff and start over. There is a cancel button on the pick list if they want to cancel the application. My question is, I know there is a way to make a dialog box topmost, but my code doesn't seem to do this. Here's my code.

cReportDialog.DoModal();
SetWindowPos(cReportDialog,WS_EX_TOPMOST,0,0,0,0,S WP_NOMOVE);

Can anybody tell me what I'm doing wrong?