I am not an Excel expert, but I have not heard of Vsearch or Hsearch, and can not find documentation on those referenced functions.
However, if what you are looking for is to have a value from one JMP data table be read and placed into another JMP table, that is readily available.
dt1 = data table(<your first data table>);
dt2 = data table(<your second data table>);
// take a value from table one and place it into table 2
dt2:column name[row number] = dt1:column name[row number];
But I am actually thinking you are looking for something like Vlookup in Excel. In JMP, the Join and/or Update platforms handle such things. When many rows and columns of data from one data table are moved into a second data table. Matching on column values or on row numbers.