Assigning Key Strokes to Activate Subroutines

I would like to allow my user to be able to press CTRL+P, CTRL+S, etc. to activate selected subroutines.

Aside from using:

    With Application
        .OnKey "^{p}", "PTOApproved"        'customizes the function when CTRL+P is pressed.
        .OnKey "^{s}", "ShortNoticePTO"     'customizes the function when CTRL+S is pressed.
        .OnKey "^{d}", "Disability"         'customizes the function when CTRL+D is pressed.
        .OnKey "^{r}", "PTORequest"         'customizes the function when CTRL+R is pressed.
    End With

Is there a way to assign the CTRL+ to the subroutines?

Thanks!

I should have asked...

Is there a way to assign the CTRL+ to the subroutines without using the .OnKey function?