$file = "disks.xlsx"

rm $file -ErrorAction Ignore

$data = $(
    New-PSItem 100 -100
    New-PSItem 1 -1
    New-PSItem 1.2 -1.1
    New-PSItem -3.2 -4.1
    New-PSItem -5.2 6.1
    New-PSItem 1000 -2000
)

$data | Export-Excel -Path $file -Show -AutoSize -NumberFormat '[Blue]$#,##0.00;[Red]-$#,##0.00'