[windows]How can i change the value of a loweord

[pavel989]

well the title kinda describes it.

I tried LOWORD(lParam) = somenum;
and it threw me an error saying that the left side valye has to be a 1-value

[Salem]

That's l-value, not 1-value (lowercase-L)

Read up on bitwise operators.
lParam &= ~0xFFFF;
lParam |= ( somenum & 0xFFFF );

[Murtan]

LOWORD is a macro, used to extract the 'low word' from a long.

HIWORD extracts the 'high word'

There is another macro that can be used to put them back together:

LPARAM MAKELPARAM(
    WORD wLow,
    WORD wHigh
);

So a call like: MAKELPARAM(somenum, HIWORD(lParam)) would be pretty close to what you want.