code: function TbsPrepareMergeCell(&$Txt, &$Loc) {
  		if ($this->ExtEquiv=='docx') {
  			// Move the locator just inside the <w:tcPr> element.
  			// See OnOperation() for other process
  			$xml = clsTbsXmlLoc::FindStartTag($Txt, 'w:tcPr', $Loc->PosBeg, false); 
  			if ($xml) {
  				$Txt = substr_replace($Txt, '', $Loc->PosBeg, $Loc->PosEnd - $Loc->PosBeg + 1);
  				$Loc->PosBeg = $xml->PosEnd+1;
  				$Loc->PosEnd = $xml->PosEnd;
  				$this->PrevVals[$Loc->FullName] = ''; // the previous value is saved in property because they can be several sections, and thus several Loc for the same column.
  				//$Loc->Prms['strconv']='no'; // should work
  				$Loc->ConvStr=false;
  			}
  		}
  	}
docs: Prepare the locator for merging cells.