Export to pdf command button save as file name question

Excel 2007
I have a button that will export the worksheet to pdf and save it as Acrobat requires. I have a network folder set up and it saves the file with the name that I have programed in the macro. I would like to have the file name set up to be what is in cell C3 then a space and the specific words.

For example, if C3 contains "123456" I want the file to be named "123456_Warranty Calculator"

I will end up using this in several worksheets which will have a different name as part of the file name (based on the worksheet name).

I would also like to have the last part of the file name be the worksheet name. ie, "Warranty Refund", "PDR Refune", etc.

I will have several users that will be using the workbook and possible saving at the same time and want each person to be able to find the one they saved instead of it being overwritten.

My macro code is as follows:
Sub SaveToPDF()
'
' SaveToPDF Macro
' Saves Worksheet to PDF
'

'
    ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
        "J:\Credit\Miami Gap Claims\Cancelation Calculation\Warranty Calculator.pdf", _
        Quality:=xlQualityStandard, IncludeDocProperties:=True, IgnorePrintAreas _
        :=False, OpenAfterPublish:=True
End Sub