Data Entry Advice Needed

Hi. I am developing a db for juvenile salmon-focussed fishery survey data and have encountered something of a conundrum which I could use some advice on. Apologies in advance for the length of the post.

Background
Juvenile salmon move from freshwater to saltwater. During this transition they require time to adapt physiologically and are thought to seek out nearshore areas with intermediate salinities, or with freshwater overlaying the saltwater. They also experience problems with elevated temperatures.

We are interested in tracking salinity and temperature information at each site where we sample for fish to aid in interpreting our catch results.

Data Collection
Our convention is to collect temp/salinity at the surface and at 3-feet below the surface wherever we beach seine (or just at the surface if the site is shallower than 3-feet). However, we use a depth-temp-salinity data-logger attached to the lead-line of a lampera net for openwater sets. The logger provides measurements of depth/temp/salinity every 5 seconds during the set, down to depths of 20-30 feet.

So, for some 'sets' we have one or two measurements of depth/temp/salinity, and for other sets we might have over one hundred measurements.

Problem

1.How best to get that data entered into the db?
2.I'm just starting to get my toes wet with VBA

Ideally, I could directly enter the values into a subform for sets with only one or two measurements, but could instead 'import' the extensive data for those sets where the logger was used. Entering the logger data manually would be ridiculously time-consuming.

Existing DB Setup
Records for temp/salinity subform/table linked to other set information by a unique Set_ID field.

Subform for depth-temp-salinity information bound to a dedicated depth-temp-salinity table. The subform is currently viewed as a continuous form.There would be one excel file for each set where a data logger was used, but no excel files for sets where no data logger was used..

My thoughts so far.

Somehow create a subform with the ability to enter up to two records manually or else click a button that imports the data from an excel file. One thought is to pop open a window to navigate to the excel file that contains the data for that set. However, I'm thinking that if I place all such excel files into a particular directory and name them using the appropriate Set_ID number convention, that maybe clicking the button with be able to find the file directly, without navigation required, and bring in the records automatically.

Is this possible? How would I go about creating a subform that provides both an 'import data' button and allows for manual data entry of up to two records?

Can anyone show me a similar example for both the data entry (form) and for how to automate the importing of data from excel files to append to an existing database table?

Aim:
The eventual goal of this is to have a command button that could be clicked on the form/subform that would produce a popup window containg a scatterplot graph of salinty versus depth. another button to produce a scatterplot of temperature versus depth. A third button to open a line graph with time on the x-axis, and temperature/salinity series on the y-axis. Before I can get there, however, I need to get the data into the table somehow.

I would appreciate any input/advice on this matter, (especially custom code! ;) ) As, I mentioned, I'm just starting out in VBA and I have a lot to learn. I know how to open a MsgBox, but have no clue on what the command is to open an explorer 'window'.

I hope the problem is sufficiently interesting to generate some response.

Cheers!