If there are always 5 "W's" and then an "R", then perhaps this?
=COUNTIF(D3:BD3,"W")-COUNTIF(D3:BD3,"R")*5
If you are not consistently 5 "W" and one "R", then try:
=IF(COUNTIF(D3:BD3,"R"),COUNTIF(INDEX(D3:BD3, MATCH(2,INDEX(1/(D3:BD3="R"),0))):BD3,"W"),COUNTIF(D3:BD3,"W"))