There are a couple ways you can take care of this in EZ Exporter.

By default, Shopify adds a hash symbol ("#") in front of the order number in the name field (e.g. #1001).

If you'd like to export just the order number without this prefix, simply select the field called order_number.

If you use a custom prefix or suffix and wanna keep them on export except for the hash/pound symbol, you can use a formula like this in the Calculated Fields:

{{ name }}.replace("#", "")

This formula will replace the "#" symbol with an empty value, essentially removing it.