Full disclosure I am dummy when it comes to REGex.  I know how to program, but REGEx escapes me.

I am working on an export and I want to look at an attribute field and if it's blank, replace it with the Raiser's Edge ID.  If its not blank, replace it with blank.  I am guessing the logic would be to create two virtual fields, one chaining off the other.  

Normally, I would do this through the API, but we are hosted, no api!

Any ideas anyone.