I can't help feeling that there must be an easier way, but if your numbers only range from 1 to 9 (e.g. 14.1-14.9, 20.1-20.9 etc., you could try the following nested fields (All the {} need to be the special "field code brace" characters you can enter with ctrl-F9, not the ordinary ones you type on the keyboard).
{ =10*{ STYLEREF 2 \s #.x } }
If you need 2 digits, things get more complicated, e.g.
{ ={ QUOTE "{ STYLEREF 2 \s }1" #.xxx }*{ IF "{ QUOTE "{ STYLEREF 2 \s }1" #.xxx }" = ".???" 100 10 } #0 }