Forms :: Open A Specific PDF File Per Record With A Command Button

I need to open a specific pdf file per record by using a command button. The pdf files will all reside in a specific folder in a partition on my hard drive. Each pdf file will have a unique four digit file name e.g 1234.pdf.The file name will match a unique number allocated to each record. This number is generated by adding 1000 to the record ID.Record 10 will therefore have an associated pdf file name of 1010.pdf.I have created a text box field , named 'TestReportID', to capture the unique four digit number per record that I assume is needed to be referred to when setting up the code to find and display the correct related pdf file.

I have set up a command button on the records form and as simple test using the hyperlink address to the folder where the pdf files reside, I can open a pdf file by clicking on the command button but it does not matter what record is open when I click the command button, it will always open the same pdf file.If I don't identify a specific file name in the hyperlink address, when I click on the button it will display a file open dialog which lists all the relevant pdf files and I can then select and open the required file.I would like to cut out that step and get the correct file to open when I click the button.