excel - How to generate a CSV for a given range on a click of form button? -

i generating csv using form button. button click code looks this:

with activesheet   lfnum = freefile   sfname = mypath & myfilename   open sfname output lfnum   each rrow in range(range("a1"), range("h1").end(xldown)).rows     each rcell in rrow.cells       soutput = soutput & cstr(rcell.value) & sdelim       = + 1     next rcell     soutput = left(soutput, len(soutput) - len(sdelim))     print #lfnum, soutput     soutput = ""   next rrow   close lfnum 

this code takes sometime generate csv file 1 million records in columns a:h.

how can make faster? , how exit form once complete?