The following formula field removes alphabets
StringVar MyField;
StringVar Strip;
Strip:= “”;
MyField := {Command.xxx};
While Length(MyField) > 0
Do
(
If IsNumeric(Left(MyField,1))
Then Strip := Strip + Left(MyField,1)
Else
If (Left(MyField,1)=”-”)
Then Strip := Strip + Left(MyField, 1);
MyField:= Mid(MyField,2);
);
Strip;