The MapInfo Raster API is .NET based so to do some scripting you need to write some .NET code like C# or VB.NET.
There are a number of sample files for the API in the MapInfo Pro installation folder under Raster\Documentation\API\Sample Code.
If you look into the sample called MapInfo.RasterEngine.Processing.Samples.cs you can find some examples on how to convert from one format to another.
It can be as simple as this:
public void Convert_Example_01(string strInFilePath, string strOutFilePath, string strDriver)
// Default RasterApiOptions
// FieldBandFilter is set to All Fields All Bands
// RasterCreationOptions will be read from default user's preference file.
// RasterFinalizationOptions will result in default settings.
RasterProcessing.Convert(strInFilePath, strOutFilePath, strDriver);
The Convert method does take a number of other parameters to give you even more control over the process.
Most of the samples from the sample files can also be found in the Raster API Documentation: Raster\Documentation\API\MapInfoProRaster.NET_SDK.chm