I would like to point out a few things to help on your script...
Using a stable version of Wine is best, so if Wine 1.8 works, it's more likely to be already downloaded than a development version of Wine.
POL_Call POL_Install_d3dx9 shouldn't be neccessary, since Lego Rock Raiders was released in 1999 and DirectX 9 wasn't released until 2002.
Also, the POL_Install_* functions should override DLLs automatically, so the POL_Wine_OverrideDLL lines also shouldn't be needed.
It appears that Lego Rock Raiders was only ever sold on CD, at least it's not on GOG.com or Steam, so you could probably remove the POL_SetupWindow_InstallMethod line---besides, POL_SetupWindow_cdrom gives the user the option to enter the location of the CD---whether it's actually a CD or just a folder.
If possible, it's best to remove start /unix on POL_Wine lines so that POL_Wine_WaitExit isn't neccessary. If start /unix is neccessary, POL_Wine_WaitBefore won't have any purpose anyway, and only POL_Wine_WaitExit will be noticable.
Wine seems to have d3drm.dll in windows/system32, so you could probably use a cp command to copy it to the installation location of Lego Rock Raiders.
POL_Wine_SetVideoDriver, if I understand correctly, is only to be used when Wine doesn't do things properly itself. Wine has gotten a lot better over the years, and this might only take more time now. If it's neccessary, though, that's fine. You might want to test just to be sure.
Lastly, POL should be able to extract the icon from the exe, so you might be able to change your POL_Shortcut line to POL_Shortcut "LegoRR.exe" "$TITLE" "" "Game;StrategyGame;"
Hopefully that helps make the script a bit easier to maintain and faster to install. Good luck!