RegEx Syntax - Find and Replace

I'm quite bad at Regular Expression syntax.  Maybe someone can help me out here.

I get a list of column names that look something like this: [BeginDateTime], [FirstName], [LastName] [Page10]

What I'd like to do is reformat these strings with spaces between lower case and upper case characters or any letter and numeric characters.  So the result would be: Begin Date Time, First Name, Last Name, Page 10

 Any ideas how this can be done with VB.NET?

Thanks.
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