Convert excel to csv ascii format

I am trying to import data to a program that required ASCII format. But, it is specifially looking for a csv comma delimited file type that includes the # sign. Here is an example: #10/12/2001#,7/6,0,7.6
I can save my excel spreadsheet as a csv (comma delimited) file, open it in Notepad and manually add all the # signs to hundreds of dates, then save it as the txt file and upload it to the program with no problem. But I don't really want to manually add all those # signs. Is there a way to get it into that format?

Thanks!