I'll give it a crack. I'll need to make a few assumptions,
which I'll describe below.

First, the assumptions:

1. you have 10 columns of data
2. your data  to be checked is always in col E .
3. by "delete", you mean you want that row made blank.

Next, the code:

01.. rrbeg = 10
02.. rrend = 500
03.. cc = 5
04.. keyword = "keep me"
05.. For rr = rrbeg to rrend
06..... txt = Cells(rr, cc)
07..... chk = LTrim(txt)
08..... If chk <> keyword Then
09......... For jj = 1 to 10
10............. Cells(rr, jj) = Empty
11......... Next jj
12..... End IF
13.. Next rr

If my assumptions are correct, then here's a quick
description of the code.

Lines 1 and 2 set the beginning and ending row numbers
where data exists.

Line 3 sets key column to col 5 (which is col "E").

Line 4 establishes the key word.

Line 5 is the outer loop. I'm not a big fan of Do While,
so I've taken the liberty to change the loop construct
to a For..Next type. Feel free to do it your way if
you prefer.

Line 6 extracts the contents of col E of the current row
and puts it in variable txt.

Line 7 performs a simple Left Trim. This is to deal with
your 23 blank  spaces issue. If the number 23 is vital, then
you could simply change Line 4 to include 23 blanks, and
then eliminate this line.

Line 8 is the compare  branch. If the comparison fails
the branch is entered to perform the delete.

Lines 9 to 11 "delete" the current row -- by setting the
cells in columns A thru J to Empty.

That should do it.
Hope this is close to what you are looking for.
Holler if it isn't.