powershell - Power shell append with export-csv -

i know question has been answered many times apologize asking again. wrote first power shell script perform aggregation task. cant figure out how append existing csv file. right script aggregating column, want modify aggregate multiple columns need append output.

my input file looks this:

salesid qty amount 1        2    5 1        3    6 2        5    9 2        6    5 

my current output is:

salesid     sum 1            5        2            11     

but want output this:

salesid sum amount  1        5     11    2        11    14 

my script:

import-csv $infilepath | group-object $groupbycolumname| %{     new-object psobject -property @{         $groupbycolumname= $_.name         sum = ($_.group | measure-object $sumcolumnname -sum).sum     } }| export-csv $outfilepath -encoding "utf8" -notype 

please me out here. thanks.

the information there access need it.

$data | group-object salesid | %{      new-object pscustomobject -property @{         salesid = $_.name         quantity = ($_.group.qty | measure-object -sum).sum         amount = ($_.group.amount | measure-object -sum).sum     } } | select-object salesid,quantity,amount | export-csv $outfilepath -encoding "utf8" -notype 

for every salesid sums of quantities , amounts. below console output before

salesid quantity amount ------- -------- ------ 1              5     11 2             11     14