usselectionid (USHORT)
This parameter should be specified only if the query is for HMQW_VIEWPORT and should otherwise be coded as NULL.
Specifies whether a res ID, ID number, or group number is being requested. The value can be any of the following constants:
HMQVP_NUMBER
usmessageid (USHORT)
Specifies the type of window to query. The value can be any of the following constants:
HMQW_INDEX
When HMQW_VIEWPORT is specified in usmessageid, a value must be specified in usselectionid to indicate whether a res ID, ID number, or group number is being requested.
pvoid (PVOID)
param2 depends on the value of param1 usmessageid.
If param1 usmessageid is HMQW_VIEWPORT, then param2 is a pointer to the res number, ID, or group ID.
If param1 usmessageid is HMQW_GROUP_VIEWPORT, then param2 is the handle of the viewport for which the group number is assigned.
If param1 usmessageid is HMQW_RES_VIEWPORT, then param2 is the handle of the viewport for which the res number is requested.
rc (ULONG)