convert multiple text to multple csv

Hi PowerShell,

How to multiple text files to multiple save csv files?

For example:
aa.txt to aa.csv
bb.txt to bb.csv

Get-Content  H:\aa.txt, H:\bb.txt | ForEach-Object {($_ -replace "\s+",",")} |Out-File -FilePath H:\aa.csv, H:\bb.csv  -Encoding OEM

Any Idea?

Thanks