Custom Cell Format: Scientific notation, dash for 0 and no alignment specifications

Hello,

I am trying to create a custom cell format that presents the numbers in scientific notation (0.00E+00) and uses a dash (-) for entries that are zero. The closest thing I could get was by modifying some of the accounting formats. It works however it right justifies the numbers and it will not change the alignment no matter what I set the cell to. It looks like it overrides the "normal" cell alignment and makes it right justified. Also, I do not want the values to line up with the decimal points. The actual numbers already do this but when it is a zero and the dash is displayed, the dash is offset to be directly under the +/- sign of the scientific notation.

I am not familiar enough with the custom number syntax to figure this out. Below is what I'm starting with but it has the mandatory right justified alignment and dash offset. Any help is appreciated. Thanks.

_(* 0.00E+00_);_(* -0.00E+00_);_(* "-"??_)



Edit:

I actually just figured it out. I removed the astrixes and that seemed to work. I sort of understand some of the syntax but I have some questions. I get the underscore part. The semi-colons seam to create a way to develop formatting for positive, negative and zero numbers in that order. Is that correct and is the primary/only usage? Also, what significance to the question marks have? Removing them does not seem to change the display.

Below is what I got to work.

_(0.00E+00_);_(-0.00E+00_);_("-"??_)