I want to generate html files that excel can open, but want to achieve the same wrap effect as using the ALT+ENTER keys within Excel.

I tried using <BR>, but it still wraps down to the next row. In the following example, I want all the manufacturer data in a single row (copy this to a text editor and name it test.xls, then double click to open it:

<table border=1>
<TR bgcolor="CCCCCC">
  <TD>DESCRIPTION</td>
  <TD>MFG</td>
  <TD>MFG PN</td>
</TR>

<TR valign="top">
  <TD>RES,0603,1/16W,100PPM,100,1%</td>
  <TD>DALE<BR>KOA SPEER<BR>KOA SPEER<BR>VISHAY<BR>VISHAY</td>
  <TD>CRCW0603-1000FRT2<BR>RK73H1JT1000F<BR>RK73H1JTE1000F<BR>CRC W06031000FRT1<BR>CRCW06031000FRT2</td>
</tr>
</table>

lizard8890 has probably long since either found a solution to this or given up, but today I enountered the same problem, found a solution here:
http://software.groupbrowser.com/t274994.html ,
and figured posting it here might help someone else find it quicker sometime in the future.

To reiterate that solution, adding

br {
mso-data-placement: same-cell;
}

to the html style sheet cause Excel to import the lines between the <br> tags into one spreadsheet cell.

Hope this helps someone sometime!