Excel 2007 : Numbers formatted as text are not being treated as text

I am working with two data sets that have two different formats
for an Assessor's Parcel Number (APN)

One is a simple eight-digit number: 00102001

The other is hyphenated, and may or may not have
an additional two digits: 001-020-01-00, or 001-020-01

I need to remove the hyphens, and truncate the left most digits in
those that contain 10 digits, to convert the hyphenated APN's to
the simple eight-digit format.

When I use the replace command to replace the hyphens with nothing,
leading zeroes are deleted. e.g.: 000-000-00-00 becomes simply 0
and 001-040-14 becomes 104014.

This is happening even when the numbers have been formatted as text.

How can I prevent the zeroes from being deleted?

Also, how can I truncate the numbers to the right-most eight digits?

Yes,

I ended up using the Left and Substitute functions to get rid of the hyphens and then, spaces,
and to truncate the numbers.

Thanks for your response.