[Natsheh]

PHP Code:

stock Seperate_Digital_Categories(const charSeperator=' ', const szString[], szValue[], len)
{
    new iStrLen = strlen(szString), index = -1, iCounts;

    while( ++index < iStrLen )
    {
        if(!isdigit(szString[ index ]))
        {
            continue;
        }

        iCounts++;
    }

    if(!iCounts)
    {
        return false;
    }

    const CATEGORY_SIZE = 3;

    new iSkip = (iCounts % CATEGORY_SIZE), iCategory = CATEGORY_SIZE - iSkip;

    index = -1;
    iCounts = 0;

    while( ++index < iStrLen )
    {
        if(!isdigit(szString[ index ]))
        {
            continue;
        }

        if(++iCounts)
        {
            if(iCounts > len)
            {
                szValue[ iCounts-1 ] = szString[ index ];
                break;
            }

            szValue[ iCounts-1 ] = szString[ index ];

            if((++iCategory % CATEGORY_SIZE) == 0)
            {
                iCounts++;
                szValue[ iCounts-1 ] = charSeperator;
            }
        }
    }

    return true;
} 


Tested works fine !

Output:-

test_cmd "Hello 500 and 999 + 464567"
OUTPUT: 500 999 464 567

TEST CODE :-

Spoiler

PHP Code:

#include <amxmodx>


public plugin_init()
{
    register_concmd("test_cmd", "test_clcmdadd");
}

public test_clcmdadd(id)
{
    new szString[32], szOutPut[64];
    read_args(szString, charsmax(szString));
    remove_quotes(szString);

    Seperate_Digital_Categories(.szString=szString, .szValue=szOutPut, .len=charsmax(szOutPut));

    server_print("OUTPUT: %s", szOutPut);
}