Make it read-only.
Look up the SetAttr statement.
e.g.
SetAttr FileName, Attributes
Attributes are one or more of:
vbNormal, vbReadOnly, vbHidden, vbSystem & vbArchive
Combine them by ORing them together.
e.g. To make C:\Autoexec.bat read-only & hidden
SetAttr "C:\Autoexec.bat", vbReadOnly Or vbHidden