To manually modify a .HPP file to include Natural Search, you need to make the following modifications:

1.   In the [OPTIONS] section, add the following line:

Custom tab="N&atural Search", SmaRTEng.SmartSearchPane

2.   In the [WINDOWS] section, modify the line for the main window (or $global_main) by adding 0x8000 (hexidecimal) to the 10th item in the list and by appending 0,,0,[ N&atural Search,SmaRTEng.SmartSearchPane] to the end of the line.

For example, if the line is

$global_main="VSA","VSA.hhc","VSA.hhk",,,,,,,0x2120,,0x3006,[200,100,1050,700],0x0,0x0,,,0,,

it should be changed to

$global_main="VSA","VSA.hhc","VSA.hhk",,,,,,,0xa120,,0x3006,[200,100,1050,700],0x0,0x0,,,0,,0,[N&atural Search,SmaRTEng.SmartSearchPane]