Instr (vbscript) Function Explanation ???

I went to Microsoft to find some info about the function Instr. I need to
perform a search with a string similar to their example I found below. Can
anyone explain to me Microsoft's example?? I am little confused by the
parameters used and the explanation it gives back to me??

Dim SearchString, SearchChar, MyPos
SearchString ="XXpXXpXXPXXP" ' String to search in.
SearchChar = "P" ' Search for "P".
MyPos = Instr(4, SearchString, SearchChar, 1) ' A textual comparison
starting at position 4. Returns 6.
MyPos = Instr(1, SearchString, SearchChar, 0) ' A binary comparison
starting at position 1. Returns 9.
MyPos = Instr(SearchString, SearchChar) ' Comparison is binary by default
(last argument is omitted). Returns 9.
MyPos = Instr(1, SearchString, "W") ' A binary comparison starting at
position 1. Returns 0 ("W" is not found).

My problem is this:

I need to scan within SearchString for blanks/spaces characters. When I
find one, then place the values to the left and right of it in seperate
columns. For example, I would need to scan 'John Smith A' and then place
'John' in FirstName column, 'Smith' in LastName column, and 'A' in MidName
column.

I think this is how my code would read, but I am confused on how to place
the results into my table to the correct columns?

my search string would be SearchString = 'John Smith A'
my SearchChar would be SearchChar = ' ' (note I am searching for a
space/blank character)

So would then my code be like:

Dim SearchString, SearchChar, MyPos
SearchString = 'John Smith A'
SearchChar = ' '
MyPos = Instr(1, SearchString, SearchChar, 0)

How do I get whatever is returned from the Instr function to a column in a
table??

Any help would be great.

Rey