excel - Change data range of Chart in PowerPoint -

i have excel file contains data , charts. i've created macro read in text file , update data , chart data ranges based on date in excel file. data range starting 5 day prior date in text file date.

this works in excel macro open powerpoint file i've created contains 2 charts linked excel file , change data range of excel chart in powerpoint presentation.

i able open powerpoint , select graph name cannot change data range.

here code using not working not throwing errors...

open powerpoint , set global oppt variable open presentation.

public sub open_powerpoint_presentation() 'opens powerpoint document excel  set objppt = createobject("powerpoint.application") objppt.visible = true  set opptfile = objppt.presentations.open(filename:=activeworkbook.path & "\dailyhealthcheck.pptx") end sub  

call routine above, change dates on labels, , attempt change source data of excel.

' open gd metrics power point, must manually closed later open_powerpoint_presentation  ' set dates in ppt slide current date opptfile.slides(1).shapes("low left date").textframe.textrange.text = format(now, "mmmm d, yyyy") opptfile.slides(1).shapes("critical issues table").table.cell(1, 1).shape.textframe.textrange.text = "grid director critical issues (as of " & format(now, "m/d") & ")"  ' change date ranges of chart if ppdrangestr <> ""     dim splitdaterange() string     splitdaterange = split(ppdrangestr, ":")     ppdrangestr = "='process per day'!$" & left(splitdaterange(0), 1) & "$" & right(splitdaterange(0), len(splitdaterange(0)) - 1) & ":$" & left(splitdaterange(1), 1) & "$" & right(splitdaterange(1), len(splitdaterange(1)) - 1)     msgbox ppdrangestr     opptfile.slides(1).shapes("processed per day chart").chart.setsourcedata source:=ppdrangestr, plotby:=xlcolumns     ' reset data labels      opptfile.slides(1).shapes("processed per day chart").linkformat.update  end if    

the string ppdrangestr "'processed per day'!$h77:$g81" same range chart in excel file (which works) using.

does know how can make macro in excel file change source data of excel chart in powerpoint source data in excel file? (if make sense?)