Extract a portion of the WSFC Cluster Log using two points of time.

Get-ClusterLogDetails

function Get-ClusterLogDetails {

    [CmdletBinding()]    
    param (
        [Parameter(Mandatory, ValueFromPipeline)]
        [string]$servername,
        [Parameter(Mandatory, ValueFromPipeline)]
        [string]$starttime,
        [Parameter(Mandatory, ValueFromPipeline)]
        [string]$endtime

    )

    begin {
        $filePath = "\\$($servername)\c$\Windows\Cluster\Reports\Cluster.log"

        if(!(Test-Path $filePath)) {
            Write-Output "Unable to connect to path [$($filePath)]"
            Write-Output 'Terminating process.'
            break;
        }
    
    }

    process {
        $startLine = Get-Content -Path $filePath | Select-String $starttime | select LineNumber -First 1
        $endLine = Get-Content -Path $filePath | Select-String $endtime | select LineNumber -First 1
        $finish = $endLine.LineNumber - $startLine.LineNumber

        try {
            # -join "`n" This needs to be in place in order for the following replace function properly convert line breaks to HTML 
            # -replace("`n","<br />") Added to preserve line breaks for HTML output
            # -replace(" ERR "," <span style='background-color: #FFFF00'>ERR</span> ") Added to highlight keyword instances
            [string]$details = @(Get-Content $filePath | Select-String $starttime -Context 0,$finish) -join "`n" -replace("`n","<br />") -replace(" ERR "," <span style='background-color: #FFFF00'>ERR</span> ")
        }

        catch {
            Write-Output $_.Exception.Message
            Write-Output 'Terminating process.'
            break;
        }
    }

    end {
        # SEND NOTIFICATION
        if ($details.Length -gt 0) {
        
            # SMTP DETAILS
            $from = '[email protected]'
            $to = '[email protected]'
            $sub = "$($servername) CLUSTER LOG REPORT - " + (get-date).ToString("yyyy-MM-dd")
            $priority = 'High' #'High or Low'
            $PSEmailServer = 'relay.domain.com'
            $port = 25

            try {
                # SEND MESSAGE
                Send-MailMessage -From $from -To $to -Body $details -Subject $sub -Priority $priority -Port $port -BodyAsHtml -ErrorAction Stop
            }
            
            catch {
                Write-Output $_.Exception.Message
                Write-Output 'Terminating process.'
                break;            
            }
        }
    }
}

# USAGE EAXMPLE:
Get-ClusterLogDetails 'ServerName' '2017/05/02-02:30' '2017/05/02-02:34'

Much thanks to @bobfrankly, Devin Rich (@dr) & @DWSR from http://powershell.slack.com for the the help and suggestions.