Conversion of png files to ani file format

You can certainly find utilities on internet that can be used to create animated cursors (.ani) from many sources, including bitmap images, such as the JPEG, PNG or TIFF files.  For example one of such cursor making utility is called AniTuner, which should be more than capable of handling png to ani conversion.

Open PNG file    Open ANI file

Related software

AniTuner icon

AniTuner

A cursor editing and conversion utility

PolyTrans|CAD+DCC

A 3D CAD translation software