update a cell every minute

Hi,

I have an application which sends stock quotes to my spreadsheet trought DDE server.

I can receive the quotes and work with it.

I need a macro that will check the time and every minute fill a cell with the stock quote. In the end of the day I want to have a column with the minutes (eg 10:00:00, 10:01:00,... up to 17:00:00 in each line) and then a series of columns with the quotes of the stock for each one of the minutes.

I tried first to create a loop and keep testing the current time and every time a minutes passes i move one line down and fill the columns with the prices.

The thing is that this method freezes my computer as the macro is on loop to check for changes in the current time....

Does anybody knows any other way of doing these?????