超暫定版 VBAでBMP2PNG完成 \(^o^)/
P5005.bmp をVBAでP5005.png に圧縮かつ多分無劣化だぜ✌

Sub 四角形角度付き1_Click()
Dim ps As String
Dim oo As Object
Set oo = CreateObject("WScript.Shell")
ps = ""
ps = ps & "Add-Type -AssemblyName System.Drawing " & vbLf
ps = ps & "$f1 = 'E:\work\P5005.bmp' " & vbLf
ps = ps & "$f2 = 'E:\work\P5005.png' " & vbLf
ps = ps & "$im =[System.Drawing.Image]::FromFile($f1) " & vbLf
ps = ps & "$im.Save($f2, [System.Drawing.Imaging.ImageFormat]::Png) " & vbLf

oo.Run "powershell -NoLogo -ExecutionPolicy RemoteSigned -Command " & ps, 1, True

End Sub