David,

>There will be a simple multiplication by a constant to convert the value to >the 10000ths of an inch measurement that the report uses.

this may be true, and I am probable finding the contanct wrong, because my new sizes are still too small.
Here is what I do:

lnlength = TXTWIDTH(lcExpr, lcFont, ;
     lnFontsize, lcfontstyle)
lnConstanct = WIDTH / lnlength

after changing the label

lnlength = TXTWIDTH(lcExpr, lcFont, ;
   lnFontsize, lcFontstyle)
REPLACE WIDTH WITH lnlength * lnConstanct