Select, Sum, convert...varchar to float?

Question

Try...

 

Msg 1035, Level 15, State 10, Line 13
Incorrect syntax near 'cast', expected 'AS'.

 

select [iznos_sa_pdv], sum(cast(Try_convert(float,[iznos_sa_pdv]))) AS ukupno
from mp_kasa_lista
 WHERE [datum] >= CONVERT(datetime, convert(varchar(10), GETDATE() ,120), 120)
AND   datum <  DATEADD(day, 1, convert(datetime, convert(varchar(10), getdate(), 120), 120))
group by iznos_sa_pdv

 Some help?

 

I need sum of column iznos_sa_pdv type varchar 255...where condition is ok