Before using a macro, you need to define it, either on the NMAKE command line or in your description file. Description-file macro definitions look like this:
macroname = macrostring
Macro names can be any combination of alphanumeric characters and the underscore character ( _ ), and they are case-sensitive. A macro string can be any string of characters.
The first character of the macro name must be the first character on the line. NMAKE ignores any spaces before or after the equal sign ( = ).
The macro string can be a null string and can contain embedded spaces. Do not enclose the macro string in quotation marks; quotation marks are used only when you define macros on the command line.