Modules & VBA :: Check For Documents With Specific Naming Structure

I want to hit a button and then it scans for a file on a server and return with a message box saying if it exists or not.

I want it so when I am on a Specific record it will search for certain requirements.

All the file names are pdf files with the same naming structure

SIT yy m(m) dd Last Name Unique Identifier
Example:
SIT 14 5 21 Smith ABCD1234567
SIT 14 10 21 Smith ABCD1234567

So I hit the button it sweeps the file path and looks for documents with this naming structure.

Last Name and Unique Identifier are fields within the db.

Last Name = txtLName

Unique Identifier = txtUniqIden

So far I have the following:

Code:
Dim strDirName As String
Dim strDirPath As String
Dim strDirName As String
Dim strDirPath As String

[Code] ....

So Far it works and I used the actual name of the items an it finds them but I need to up each record.

I have no clue how to begin with the strDirName. How to get it to scan the file name in a specific format.