The automatic number can count both total pages and pages in current section. You want the latter. If your sections are properly set up, all you need to do is to change the footer option to count pages of the section. This page explains how to do it in detail for Word 2010. Relevant excerpts:
If your document has only two sections in it (one for the title page and the other for the rest of the document) you can simply change the NUMPAGES field to the SECTIONPAGES field. This field returns the total number of pages in the section (the main body of the document) instead of the total page count for the document. Your field code would, essentially, look like this: Page { PAGE } of { SECTIONPAGES }
To insert the fields described above, use the following approach:
Display the Insert tab of the ribbon. In the Text group, click Quick Parts and then choose Field. From the resulting dialog box select the field name from those available. When you click your mouse on OK, the field you requested is inserted in your document.