Use any technique to copy to the clipboard a set of regions that together span 1 worksheet page or less.
When you paste the clipboard into a new WORD document, the WORD page settings are automatically updated to match those of the Mathcad worksheet. Since the pasted content is less than the height of one page, the regions are pasted into the WORD page without any overlap.
However, pasting in a WORD document with existing content, if there is previous content below the insertion point, or if the space before the end of the page is not enough to contain the pasted content, then this may cause overlap or misplaced regions. It is up to you to ensure that there is enough space for the pasted content before you paste.