Sorry it took so long to get back to you on this. I asked a colleague for help with this since it is not one I'm familiar with and he was able to help work out a solution which is this.
You will need to make use of the string replace function for MySQL within the query itself like this:
WHERE REPLACE(REPLACE(products.ProductName,'-', ''),' ', '') LIKE '%f34%'
This example would is for a ProductName column in a products table. To use this approach with DataAssist Search you will need to adjust the code that is written to the page. Where the column is listed in the server behavior you should replace it with the replace like this:
$WADbSearch1->addComparisonFromEdit("REPLACE(REPLACE(ProductName,'-', ''),' ', '')","S_custom","AND","Includes",0);
If you need further help implementing this please post back with the $WADbSearch1 line of code from your results page and I can show you how to implement it.