This is not only a VbScript problem but also a regex problem.
The first error is a mistake in your script:
For Each strMatch in colMatches
Wscript.Echo strSearchString
Next
You are printing
strSearchString
(the line read from the file) instead of
strMatch
(each match).
To get only the matched parts, enclose them with parentheses. But that requires to include the following characters until a word separation character occurs. In your case you can simply match for "89" followed by one or more digits:
objRegEx.Pattern = "(89\d+)"
If you know that the total length is always 20, you can also specify that there must be 18 following digits:
objRegEx.Pattern = "(89\d{18})"
See also
Regular Expression Syntax (Scripting)[
^].