Delphi 2009 MS Build headaches - delphi

Question

does anyone know of any good description of delphi's build system? (i know it's using MS Build.) i'm using delphi 2009.
i wanted to set up a variation of the Debug build configuration that (often) has different defines (d2009 seems to call them "preprocessor symbols").
the problem i'm having is that--even though i turned off "inherit" for "Base" and "Debug"--have only very limited control. for example, i can't get rid of FastMM_.
<PropertyGroup>
<ProjectGuid>{D7FE7347-8E2C-438C-A275-38B8DA9244B0}</ProjectGuid>
<ProjectVersion>12.0</ProjectVersion>
<MainSource>oca.dpr</MainSource>
<Config Condition="'$(Config)'==''">Debug</Config>
<DCC_DCCCompiler>DCC32</DCC_DCCCompiler>
</PropertyGroup>
<PropertyGroup Condition="'$(Config)'=='Base' or '$(Base)'!=''">
<Base>true</Base>
</PropertyGroup>
<PropertyGroup Condition="'$(Config)'=='Release' or '$(Cfg_1)'!=''">
<Cfg_1>true</Cfg_1>
<CfgParent>Base</CfgParent>
<Base>true</Base>
</PropertyGroup>
<PropertyGroup Condition="'$(Config)'=='Debug' or '$(Cfg_2)'!=''">
<Cfg_2>true</Cfg_2>
<CfgParent>Base</CfgParent>
<Base>true</Base>
</PropertyGroup>
<PropertyGroup Condition="'$(Base)'!=''">
<DCC_StringChecks>off</DCC_StringChecks>
<DCC_MinimumEnumSize>4</DCC_MinimumEnumSize>
<DCC_RangeChecking>true</DCC_RangeChecking>
<DCC_IntegerOverflowCheck>true</DCC_IntegerOverflowCheck>
<DCC_UNIT_PLATFORM>false</DCC_UNIT_PLATFORM>
<DCC_SYMBOL_PLATFORM>false</DCC_SYMBOL_PLATFORM>
<DCC_DcuOutput>.\dcu</DCC_DcuOutput>
<DCC_UnitSearchPath>C:\Prj\Lib\AutoQADocking\Delphi2009.Win32\Lib;$(BDS)\Source\DUnit\src;$(DCC_UnitSearchPath)</DCC_UnitSearchPath>
<DCC_Optimize>false</DCC_Optimize>
<DCC_DependencyCheckOutputName>oca.exe</DCC_DependencyCheckOutputName>
<DCC_ImageBase>00400000</DCC_ImageBase>
<DCC_UnitAlias>WinTypes=Windows;WinProcs=Windows;DbiTypes=BDE;DbiProcs=BDE;DbiErrs=BDE;$(DCC_UnitAlias)</DCC_UnitAlias>
<DCC_Platform>x86</DCC_Platform>
<DCC_E>false</DCC_E>
<DCC_N>false</DCC_N>
<DCC_S>false</DCC_S>
<DCC_F>false</DCC_F>
<DCC_K>false</DCC_K>
</PropertyGroup>
<PropertyGroup Condition="'$(Cfg_1)'!=''">
<DCC_PentiumSafeDivide>true</DCC_PentiumSafeDivide>
<DCC_Optimize>true</DCC_Optimize>
<DCC_IntegerOverflowCheck>false</DCC_IntegerOverflowCheck>
<BRCC_Defines>MadExcept;FastMM;$(BRCC_Defines)</BRCC_Defines>
<DCC_AssertionsAtRuntime>false</DCC_AssertionsAtRuntime>
<DCC_LocalDebugSymbols>false</DCC_LocalDebugSymbols>
<DCC_Define>RELEASE;$(DCC_Define)</DCC_Define>
<DCC_SymbolReferenceInfo>0</DCC_SymbolReferenceInfo>
<DCC_DebugInformation>false</DCC_DebugInformation>
</PropertyGroup>
<PropertyGroup Condition="'$(Cfg_2)'!=''">
<DCC_DebugInfoInExe>true</DCC_DebugInfoInExe>
<BRCC_Defines>FastMM</BRCC_Defines>
<DCC_DebugDCUs>true</DCC_DebugDCUs>
<DCC_MapFile>3</DCC_MapFile>
<DCC_Define>DEBUG;FastMM_;madExcept;$(DCC_Define)</DCC_Define>
</PropertyGroup>
i even had to edit it today with notepad to get rid of a DCC define that the delphi UI doesn't seem to give access to. (it said "From Delphi Compiler" for the item i couldn't remove.)
does anyone know a good primer on the use of this feature in delphi?
thank you!