I think you will need to use VB - and MORE. Ms. Access always truncates trailing blanks in database fields. You will need to set up some other obscure process to maintain the information, such as a new field (integer) which could hold the number of spaces which SHOULD be in the all blanks field. If the (real) field is populated, just ignore this "special" information, otherwise use it to determine the number of spaces the empty field should have.
The alternative is to re-think the use/signifance of the blanks in the original system and re-design the process to do this another way. If you are just using the existing data as a data consumer, you probably don't have any real choice but to do the count thing. If this is a conversion effort from some other process / system to Ms. Access, you should be able to influence the process design to avoid the awkward use of blank fields.
[sig]<p>MichaelRed<br><a href=mailto:mred@duvallgroup.com>mred@duvallgroup.com</a><br>There is never time to do it right but there is always time to do it over[/sig]