Google spreadsheet script functions (2)

Very simple project... I need two Google spreadsheet script functions that can be called from the cell of one worksheet to access data in the table of another sheet. The script functions include... 1) Function – LookupRow(ColName, WorkSheetName, row) a. Return the last value in the last row for a column by column name or column letter in given worksheet. Optionally, return the value in the previous or following row(s). Example -1 or +1 or any other value. Return valid date (if row cannot be found) return 0. 2) Function – LookupRowDate(ColName, WorkSheetName, date, row) a. Return the value in the cell in a specific column for a specific row by date found in column A. Optionally, return the value in the previous or following row(s). Example -1 or +1 or any other value. Return valid date (if row cannot be found) return 0. Sample data is provided in the attached file but will actually reside in a Google spreadsheet document. Please provide a sample of similar work so that I know that you can actually do this job.