powershell regex replace using variable parameters when calling replace

Question

I wondering how to make the following powershell code work with regular expressions. For example I want to call it like this:

rename_file -OneFile proj1_file.txt -Replace0 "^proj1_" -Replace1 "mynewproj_"

The problem is that as soon as I add the regular expression caret (^) my function stops matching for the replace function... If I remove the caret anchor the code works... but is dangerous because its not anchored to the front of the string... I really want the regular expressions chracters to work when passing the string in to this function...

Here's my powershell code...

    $script:TotalRename = 0
    
    function rename_file {
        param(
        [string]$OneFile,
        [string]$Replace0,
        [string]$Replace1
        )
        
        #$NewName = $OneFile.Replace($Replace0, $Replace1)
         $NewName = $OneFile -replace $Replace0, $Replace1
    
        if ($NewName -eq $OneFile) {
            write-host "NoChange $OneFile"
            return
        }
        
        $script:TotalRename = $script:TotalRename + 1
            
        write-host "rename  $OneFile => $NewName"       
    }