how to hack views to prefix a character to an exposed filter

Hi..,

I need a way to prefix a chracter to an exposed filter giving me ("-" . exposed_filter_content) e.g. .... end result "-S10"

I have a field with UK postcode data, one partial post code per line and want the visitor to enter a partial postcode to search for.

Using views this is not a problem, but what is a problem is having "LS10" and "S10" when "s10" is seached for, both entries are returned. I only want complete lines to be considered in the search, so adding the "-" to the beginning of each line as in.. "-LS10" & "-S10" would make this work, if I can find a way to hack the views code and prefix the exposed filter results with a "-" before the SQL statement is created.

Any Ideas? Please..... please.......... PLEASE :)

Regards

Steve