DIMX $gridname, gridmap(int, int, varstr)
DIMX $gridname, gridmap(int, varstr, varstr)
The first variation indexes both the row and column by integer values; range is -10M to +100M for the rows and -10K to +100K for the columns. The second variation uses a numeric row index but an alphanumeric column index—i.e. column names in a result set, column headers in spreadsheet, etc.