Hcan i pass where condition in below query?

Question

DECLARE @WFavailablequery nVARCHAR(max)

DECLARE @WFavailablecolumn nVARCHAR(max)

SELECT @WFavailablecolumn = STUFF(( SELECT'],['+ Tradecat FROM mstr_tradecategory order by '],[' + convert(nVARCHAR(max),Tradecat) FOR XML PATH('')), 1, 2, '') + ']'

SET @WFavailablequery ='SELECT VendorName,VendorCode,' + @WFavailablecolumn + ' FROM( SELECT wf.VendorCode,VendorName,Tradecat

FROM dbo.mstr_workforce as wf inner join mstr_vendor as v on v.VendorCode=wf.VendorCode

left outer join mstr_tradecategory as tc on tc.TrcatCode=wf.Category where v.VendorCode='+LTSBV000001+')

mstr_workforce PIVOT (count(Tradecat) FOR Tradecat IN ('+@WFavailablecolumn+')) AS pvt'

EXECUTE (@WFavailablequery)

Hi Please help me any one ,

I dont know how pass where condition in above query