There are too many 'unknowns', from our perspective, in relation to your question - that's why nobody has yet responded.
You have a list of proteins. You want to get the gene expression of the genes relating to these proteins. In which tissues are you interested?; in which diseases are you interested?; have you considered that issue that gene and protein names can be entirely different?
A useful resource to look up the expression of genes in different tissues is: Genotype-Tissue Expression (GTEx). You can download data from GTEx via the Datasets tab
Apart from that, there are tens of thousands of GEO datasets, so, you an start searching Here to find out which datasets would be of most interest to you.
Kevin