[Arkshine]

You have to check when WeaponList is being registered, then getting the return value.
RegUserMsg is going to be called for all the messages at once.

The game does that essentially:

Spoiler

void LinkUserMessages()
{
	if (gmsgCurWeapon)
		return;

	gmsgCurWeapon     = REG_USER_MSG("CurWeapon", 3);
	gmsgGeigerRange   = REG_USER_MSG("Geiger", 1);
	gmsgFlashlight    = REG_USER_MSG("Flashlight", 2);
	gmsgFlashBattery  = REG_USER_MSG("FlashBat", 1);
	gmsgHealth        = REG_USER_MSG("Health", 1);
	gmsgDamage        = REG_USER_MSG("Damage", 12);
	gmsgBattery       = REG_USER_MSG("Battery", 2);
	gmsgTrain         = REG_USER_MSG("Train", 1);
	gmsgHudTextPro    = REG_USER_MSG("HudTextPro", -1);
	gmsgHudText       = REG_USER_MSG("HudText", -1);
	gmsgSayText       = REG_USER_MSG("SayText", -1);
	gmsgTextMsg       = REG_USER_MSG("TextMsg", -1);
	gmsgWeaponList    = REG_USER_MSG("WeaponList", -1);
	gmsgResetHUD      = REG_USER_MSG("ResetHUD", 0);
	gmsgInitHUD       = REG_USER_MSG("InitHUD", 0);
	gmsgViewMode      = REG_USER_MSG("ViewMode", 0);
	gmsgShowGameTitle = REG_USER_MSG("GameTitle", 1);
	gmsgDeathMsg      = REG_USER_MSG("DeathMsg", -1);
	gmsgScoreAttrib   = REG_USER_MSG("ScoreAttrib", 2);
	gmsgScoreInfo     = REG_USER_MSG("ScoreInfo", 9);
	gmsgTeamInfo      = REG_USER_MSG("TeamInfo", -1);
	gmsgTeamScore     = REG_USER_MSG("TeamScore", -1);
	gmsgGameMode      = REG_USER_MSG("GameMode", 1);
	gmsgMOTD          = REG_USER_MSG("MOTD", -1);
	gmsgServerName    = REG_USER_MSG("ServerName", -1);
	gmsgAmmoPickup    = REG_USER_MSG("AmmoPickup", 2);
	gmsgWeapPickup    = REG_USER_MSG("WeapPickup", 1);
	gmsgItemPickup    = REG_USER_MSG("ItemPickup", -1);
	gmsgHideWeapon    = REG_USER_MSG("HideWeapon", 1);
	gmsgSetFOV        = REG_USER_MSG("SetFOV", 1);
	gmsgShowMenu      = REG_USER_MSG("ShowMenu", -1);
	gmsgShake         = REG_USER_MSG("ScreenShake", 6);
	gmsgFade          = REG_USER_MSG("ScreenFade", 10);
	gmsgAmmoX         = REG_USER_MSG("AmmoX", 2);
	gmsgSendAudio     = REG_USER_MSG("SendAudio", -1);
	gmsgRoundTime     = REG_USER_MSG("RoundTime", 2);
	gmsgMoney         = REG_USER_MSG("Money", 5);
	gmsgArmorType     = REG_USER_MSG("ArmorType", 1);
	gmsgBlinkAcct     = REG_USER_MSG("BlinkAcct", 1);
	gmsgStatusValue   = REG_USER_MSG("StatusValue", -1);
	gmsgStatusText    = REG_USER_MSG("StatusText", -1);
	gmsgStatusIcon    = REG_USER_MSG("StatusIcon", -1);
	gmsgBarTime       = REG_USER_MSG("BarTime", 2);
	gmsgReloadSound   = REG_USER_MSG("ReloadSound", 2);
	gmsgCrosshair     = REG_USER_MSG("Crosshair", 1);
	gmsgNVGToggle     = REG_USER_MSG("NVGToggle", 1);
	gmsgRadar         = REG_USER_MSG("Radar", 7);
	gmsgSpectator     = REG_USER_MSG("Spectator", 2);
	gmsgVGUIMenu      = REG_USER_MSG("VGUIMenu", -1);
	gmsgTutorText     = REG_USER_MSG("TutorText", -1);
	gmsgTutorLine     = REG_USER_MSG("TutorLine", -1);
	gmsgTutorState    = REG_USER_MSG("TutorState", -1);
	gmsgTutorClose    = REG_USER_MSG("TutorClose", -1);
	gmsgAllowSpec     = REG_USER_MSG("AllowSpec", 1);
	gmsgBombDrop      = REG_USER_MSG("BombDrop", 7);
	gmsgBombPickup    = REG_USER_MSG("BombPickup", 0);
	gmsgSendCorpse    = REG_USER_MSG("ClCorpse", -1);
	gmsgHostagePos    = REG_USER_MSG("HostagePos", 8);
	gmsgHostageK      = REG_USER_MSG("HostageK", 1);
	gmsgHLTV          = REG_USER_MSG("HLTV", 2);
	gmsgSpecHealth    = REG_USER_MSG("SpecHealth", 1);
	gmsgForceCam      = REG_USER_MSG("ForceCam", 3);
	gmsgADStop        = REG_USER_MSG("ADStop", 0);
	gmsgReceiveW      = REG_USER_MSG("ReceiveW", 1);
	gmsgCZCareer      = REG_USER_MSG("CZCareer", -1);
	gmsgCZCareerHUD   = REG_USER_MSG("CZCareerHUD", -1);
	gmsgShadowIdx     = REG_USER_MSG("ShadowIdx", 4);
	gmsgTaskTime      = REG_USER_MSG("TaskTime", 4);
	gmsgScenarioIcon  = REG_USER_MSG("Scenario", -1);
	gmsgBotVoice      = REG_USER_MSG("BotVoice", 2);
	gmsgBuyClose      = REG_USER_MSG("BuyClose", 0);
	gmsgSpecHealth2   = REG_USER_MSG("SpecHealth2", 2);
	gmsgBarTime2      = REG_USER_MSG("BarTime2", 4);
	gmsgItemStatus    = REG_USER_MSG("ItemStatus", 1);
	gmsgLocation      = REG_USER_MSG("Location", -1);
	gmsgBotProgress   = REG_USER_MSG("BotProgress", -1);
	gmsgBrass         = REG_USER_MSG("Brass", -1);
	gmsgFog           = REG_USER_MSG("Fog", 7);
	gmsgShowTimer     = REG_USER_MSG("ShowTimer", 0);
	gmsgHudTextArgs   = REG_USER_MSG("HudTextArgs", -1);
}