Impossible query with SQL? or not?

This may be impossible to do with sql (or easy - i'm a beginner) but
here goes -
i need to search one field in a column for more than one match to the
input string.
to elaborate: i have a field with multiple keywords entered into it and
i need my
search to look for matches of substrings of input to substrings of text
in the field.
my current search will find any one chunk of text that matches.

here's an example:
i have a keyword field in my database with the following string
'xxx yyy zzz'

my keyword search engine currently will find 'xxx' alone, 'yyy' alone,
'zzz' alone or 'xxx yyy' or 'yyy zzz' - or even 'y zzz' etc.
in other words any one chunk of text.

but it WILL NOT find 'xxx zzz' -

i need to make it look at a field multiple times for discrete chunks of
text.

i have guessed that the input text may need to be parsed but don't know
how to go about it.

otherwise i would just do a select on the field with multiple conditions
specified.

sorry this is so long - but i wanted to be as clear as possible.

any help would be GREATLY! appreciated.

by the way - i'm working with a piece of pre existing commerce software
and am prevented from simply setting up a table structure of my own and
am
limited by a finite number of available data fields prewritten in the
VBscripts (which
are what i'm altering right now)

kind of a headach, huh?

thanks.