What does the open statement look like using this technique? OPEN(UNIT = __, FILE = ???, STATUS=’NEW’)?

A: Gfortran does not accept this block

      write(file_name,'cp',(i5.5),'.out') ITN
      open  (67,file = file_name)

Gives, ERROR, file tag must be of type CHARACTER

Can someone else help with this?

A: See the answer above. Basically the way you have written the variable file_name is incorrect.

WRITE(file_name,fmt='(A2,I0,A4)')'cp',ITN,'.out'
OPEN(UNIT=67, file=file_name, status='new')

Assuming that ITN has been declared as an integer and given a value.