LOOKUPVALUE(MID Question

[gmazza76]

Good Afternoon,

Can you use MID in a lookupvalue formula in Power Pivot?

I am trying to use the following, to try and find the initial (2,2) and then match them against a source table to the full name.

=LOOKUPVALUE(MID('Sheet'[Column1],2,2),'SourceId'[SourceIitials],'SourceId'[SourceFName])

Kind of lost on how to do this one.
Thanks for the help in advance.

thanks
Gavin