Need Sales Order Header Script to compute Standard Cost based Margin on ENTIRE Order, on totals tab.

I'm looking for existing script I can use to simplify our need to run a custom report during our quoting process for every order.  Can anyone help me create a script that will calculate the entire Gross Profit/Margin for the whole Sales Order and display it in a read only field either during Sales Order Detail entry or on the Totals Tab of sales order entry.  I've seen some similar type of scripting (for individual lines) or that displays message boxes (don't want message boxes popping).  I just want a calculation that I can easily write in a custom crystal report that fires as each line changes and records that calculated field in a SO HEader UDF and then displays that field in real time during order entry.  This sounds so simple, right? 

I don't script - so it seems hard to me.

I might be willing to pay someone for this - before I waste time hacking my way through it.  :)

Thanks a head of time to all the great people who contribute in these forums.  I love it.  So helpful!

Brad