an example can be found on AMOSPro_Examples:Examples/H-0/Help_8.AMOS
SETs the PATTERN to be used for filling shapes by choosing a pattern number. A value of zero is the normal setting, which completely fills shapes with the current INK colour. If the pattern number is greater than zero, one of the built-in patterns is used. If it is less than zero, a clipped version of one of your Bobs will be adapted as your fill pattern.
Set Pattern number