Need Help with loops.

Hello,

I'm new to VB and am currently working on a project where you enter in a start date and then how many days you want to go back. After this is done I would like to be able to click on a command button and have it run a series of loops that will do the following

-take a date and enter it cell H2

-below this in a range of H4:L510 there are a bunch of formulas that pull information using the date provided above. it takes them a couple of secounds to run, and while they are searching they display"#N/A Requesting Data..." I would like to have a loop that checks this until there are no more "#N/A Requesting Data..." before going on to the next step.

-Once all the data has hit I need to run a function that sees if value in col J >= there counter parts in col H (this variable can be called HIGH), as well as if value in col K >= there counter pars in col I (this variable can be called LOW).

-Once this is completed i need to take the sum of HIGH & LOW and imput HIGH into cell C8 and LOW into cell D8

-Once this is compeated i need to go one cell down and one row back, so from C8 i need to go to B9 take this value (which is a date) and plug it back into H2 and do this over and over again until the value in col B = ""



hope the logic and steps in this make since.... please let me know if you need more info.
And THANK YOU SO MUCH!!!