Please be aware that your suggestion of using 

  .*

[download]
will greedily include everything to the end of the string. The OP specifically states 8 digits, with possible whitespace breaking the digits into groups of 4.

While your suggestion works on your test data, it will not work on certain other data.

In reply to Re^2: How to write a regular expression to extract a number from an embedded string? by pbeckingham
in thread How to write a regular expression to extract a number from an embedded string? by jwking

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