How to exit for loop in excel-vba -

my dataset

i want make them

please @ first row.

my code is

private sub commandbutton1_click()   dim mycolinstance, long   dim myworksheetlastcolumn byte   myworksheetlastcolumn = worksheets(1).cells(1, columns.count).end(xltoleft).column    = 1 myworksheetlastcolumn     mycolinstance = colinstance("preference", i)     cells(1, mycolinstance).value = "preference" &    next  end sub  function colinstance(headingstring string, instancenum long)   dim colnum long   on error resume next   colnum = 0    x = 1 instancenum      colnum = (range("a1").offset(0, colnum).column) + application.worksheetfunction.match(headingstring, range("a1").offset(0, colnum + 1).resize(1, columns.count - (colnum + 1)), 0)   next    colinstance = colnum  end function 

the problem while running code, shows error because loop not complete. can do?

can way? seems me adding suffix headers in first row...

sub updatecolumnheaders()     dim headers range, header range, suffixes range, suffix range, integer      set headers = range(cells(1, 1), cells(1, range("a1").end(xltoright).column))     set suffixes = range("a1:a" & range("a1").end(xldown).row)      = 1      each header in headers         if header = "preferences"             header = header & suffixes(i)             = + 1         end if     next end sub